For many, the EarthRoamer is the gold standard of overland rigs—a beautifully engineered, go-anywhere luxury vehicle built to handle extreme terrain and climate with total independence. But with prices soaring over $700,000, it remains a dream rig for all but a lucky few.
So, while we love and appreciate what the EarthRoamer is, this project started with this simple question:
Can you build something that gets you 80% of the EarthRoamer experience for 20% of the cost?
We believe the answer is yes!
In this series, we’ll walk you through how we’re doing exactly that—starting with the 2021 Dynamax Isata 5 28SS with the Explorer Package and factory 4WD, which we purchased as the platform for our EarthRoamer-style rig. In Part 1, we’ll explain why this was the ideal choice for our goals, our budget, and our long-term plans.
What We Were Looking For
Before diving into specifics, here’s what we needed from our base rig:
- Four-season capability, including dual-pane windows, added insulation, and heated holding tanks.
- Factory-installed off-grid power, such as solar and lithium batteries.
- A rugged diesel chassis with true 4WD—not AWD or electronic traction substitutes.
- Comfortable interior space for long-term overland travel.
- High build quality and serviceability, ideally from a well-known manufacturer.
- And critically: A total cost under $150,000.
We knew that the Buckstop Legacy Single Wheel Conversion—which includes suspension, bumper, and bodywork—would cost $20,000, so our budget for the base rig had to be under $130,000.
After months of searching and some tough negotiations, we found the perfect unit at La Mesa RV in Port St. Lucie, Florida.
We closed the deal at $129,740 for a 2021 Dynamax Isata 5 28SS with just 22,200 miles and the sought-after Explorer Package and factory 4WD. It was exactly what we needed!
Why We Chose the Dynamax Isata 5 28SS
1. Ram 5500 Chassis with Factory 4WD
A top priority for us was real, selectable four-wheel drive. The Isata 5 is built on the Ram 5500 SLT chassis, which came equipped from the factory with 2WD, 4WD High, and 4WD Low—not just traction control gimmicks, but a real transfer case and locking capability.
Paired with the 6.7L Cummins I6 Turbo Diesel, producing 360 horsepower and 800 lb-ft of torque, this truck-based platform is overbuilt and under-stressed—exactly what you want when hauling thousands of pounds into rugged terrain.
The Aisin 6-speed automatic transmission, heavy-duty axles, and 10,000 lb towing capacity round out what is essentially a commercial-grade chassis with some off-road capability. We also spoke to Dusty at Buckstop and he mentioned this was one of the chassis that have worked well with their conversion.
2. Explorer Package: All-Season Capability
Where most motorhomes fall short, the Explorer Package excels. This factory option set the Isata 5 apart from the pack with a suite of true four-season upgrades, including:
- Dual-pane, frameless windows to reduce condensation and heat loss
- Thermal insulation in the walls, floor, and roof
- Heated holding tanks and utility bays
- A secondary 12V tank heater with thermostat control
- Insulated cab curtain for cold-weather efficiency
- Temperature monitoring inside the utility bay
These features allow the rig to operate in freezing conditions without risk of freezing critical systems, making it suitable for true year-round travel.
3. Factory Off-Grid Power System
One of the biggest appeals of the Explorer Package is that it comes off-grid ready, straight from the factory:
- 800 watts of solar with an MPPT charge controllers
- 400Ah of lithium batteries with integrated heaters
- 2,800W pure sine inverter (3,900W peak)
- Cummins Onan QD8000 quiet diesel generator
This is the kind of system most RVers spend months and thousands of dollars to retrofit. With our Isata 5, it was already installed and integrated. The generator taps into the 52-gallon diesel fuel tank, giving us backup power for days even in extended cloudy weather.
Check out this video from Dynamax that explains this package a bit more.
4. Comfortable Interior for Life on the Road
Functionality is crucial, but so is comfort—especially if you’re planning to live on the road or travel for weeks at a time. The Isata 5 28SS strikes a balance between practicality and livability with:
- A 60” x 75” queen bed with gel-infused memory foam
- Large dry bath with a residential-style shower and porcelain toilet
- Full kitchen, including a 9 cu. ft. refrigerator, gas range, and convection microwave
- Fold out couch and an overhead bunk
- Smart TV and sound bar
- High-end cabinetry, soft-close drawers, and a clean modern interior
One key feature: the coach is fully functional even when the slide is in—critical for overnighting in tight or stealthy spots.
5. Exterior Utility and Storage Features
The exterior utility setup was another selling point. This coach offers:
- Rotocast, heated storage compartments with LED lighting
- Side-hinged aluminum exterior doors with paddle latches
- Electric patio awning with integrated LED lighting and wind-sensing auto-retract
- Four-point auto-leveling hydraulic jacks with Bluetooth control
- 50-amp shore power service with surge protection
Everything about the unit is designed to be usable, convenient, and reliable—from the storage bays to the power systems to the entry and awning systems.
Our Numbers So Far
| Item | Cost |
|---|---|
| 2021 Dynamax Isata 5 28SS (22,000 miles) | $129,740 |
| Buckstop Legacy Kit (Stay Tuned For Part 2) | $20,000 |
| Total Build Cost | $149,740 |
With our total budget cap at $150K, we landed right where we needed to be—and we’ve got a powerful, capable, four-season coach to show for it.
What’s Next: Buckstop Single Wheel Conversion (Part 2 Preview)
While the Isata 5 is excellent in stock form, we’re taking it a step further to maximize off-road performance, durability, and aesthetics. The pic shown here is a sneak peak.
In Part 2, we’ll cover the installation of the Buckstop Legacy Single Wheel Conversion Kit, which includes:
- 4-link rear suspension system with tuned coilover shocks
- Heavy-duty steel front bumper with winch mount and recovery points
- Custom front and rear fender flares to accommodate wide single tires
- Conversion to 41″ all-terrain tires on aluminum wheels
This modification not only improves ground clearance and ride quality but also removes the limitations of a dual rear wheel setup in soft or uneven terrain—bringing our rig even closer to true expedition vehicle status.
Learn more about the kit we’re using at:
👉 Buckstop Legacy Kit Overview
Final Thoughts
The 2021 Dynamax Isata 5 28SS with the Explorer Package and factory 4WD gave us the ideal starting point for building a real-deal, all-season, off-grid adventure vehicle. With the key systems already installed—solar, lithium, heated tanks, and diesel generator—we skipped thousands of dollars in retrofits and upgrades.
By pairing this platform with the Buckstop Legacy Kit in Part 2, we’re building a sub-$150K rig that can confidently go head-to-head with builds costing three to five times more.
Stay tuned for the next installment as we document the single rear wheel conversion, tire fitment, suspension tuning, and more. The EarthRoamer dream is alive—and it’s attainable. Also, we plan to continue to improve the capability of this rig over the course of the coming months with a goal to create a capable overlanding rig on a relatively attainable budget.
