I think it is natural that we are seeing more Earthroamers for sale. They continue to make more, and they usually change hands every 1-2 years, much like expensive supercars do. It's not that the toy isn't good—it's that this crowd always has a new one, and campers/RVs/overland stuff is coming off a massive growth period after COVID and is settling into a new normal.
We are on year three of owning ours, with no intention to sell. I will say that after this period of ownership, the ability for an ER to trigger the insecurities of others continues to impress. If I had a dollar for every time someone came up to me at a gas station and told me they could build it for less, I could probably buy another ER.
I've had mine for just shy of a decade and a half. It is rare that I park or fill up and someone doesn't walk up to say hi, nice camper, heavy truck tires, how do you change em?, man 90 gallons of diesel in Oregon is a plane ticket, etc. I must say I have never had anyone come up and say they could build it for less, or anything else even remotely similar, but if I met such a person, I would give them my contact info and ask them to give me a call when they roll out Unit 1 for sale so I can check it out: I'm always on the hunt for a new rig but haven't found one better. Earthroamer operates in a niche they've carved that no one really seems to be going after (why I have no idea)...and they're making money running their company. The late ER CEO Bill Swails had a pretty straightforward concept and, esp. given the [still] mediocre US options for 4WD diesel trucks that can handle some weight, did a decent job moving the ball forward for American-made offroad campers that a small family can camp/live in comfortably through 4 seasons. I'm pretty familiar with all aspects of my rig and maintain it mostly by myself. I really don't know if someone could do it for less. I doubt I could, especially with all the comfort-oriented bells&whistles the modern American overlander seems to want/need not to mention how much it costs to design/build/test something that is street legal let alone lets you keep your OEM truck warranty. There are definitely some decent DIY builds out there, who knows how they handle 14+ winters of cold weather, icy roads and climbing/descending passes...hopefully great though I know many say to hell with that winter camping stuff. When ER started out, they weren't significantly more expensive than a Sportsmobile. You could pick exactly what options you wanted which was an easy way to save. Alas, mission creep seems to be hardwired into the American way for a lot of folks and the new roamers are $$$$ and over the top complex, just like most things these days (homes, appliances, F-35 jets, going to college, etc.). Personally, I decided to get mine after I spent a chunk of time in it, under it and looking throughout at the plumbing and other systems and determining that it would do a good job in the cold unlike anything else I had seen...and in 2008 I was hard-pressed to find a 4x4 camper (Sprinters weren't even being sold in the US with AWD yet) that could operate in winter (cooking, hot shower, toilet, etc.) and drive over mountain passes, chain up and do snow-covered roads, etc. reliably. I didn't need a serious off-roader, more a ski-house/base camp on wheels that could roam the paved/dirt roads of the US and Canadian Rockies year round. My go-to "offroad" tricks are reading maps, driving really slow well & tirelessly, turning around/backing up with no ego bruise and being relatively quick with tire chains any time the route ahead looks dodgy. I had read some about Unicat and some other European companies with more capability and proven performance history overseas but vehicle availability, parts and maintenance seemed to be challenging not to mention being twice as expensive as an ER then. Some US companies out there now might be building the equivalent or better, maybe even for less, but I haven't really seen much of them, maybe GXV or Bliss though of course "equivalent or better" is subjective.