Wow, Americans are rich. We boondock all over Mexico, the U.S. and we did a trip to Canada for a couple of months. We have a 24ft travel trailer, purchased new (model 2008 purchased in 2010) from a dealer that went bankrupt. We paid 8K, has two slideouts, etc. Perfect for us. We tow with our daily driver that we have had since 2008.
We don't spend much, our big expense in Mexico right now is fuel. I don't think you have to spend a lot to rv. Depends on how good of a shopper you are. Match your rv to your budget.
Boondocking takes to places most people will never get to see and usually they are right around the corner.