No, but they might have some too. PDO is on Mariano Matamoros. Continue South on Campeche until you get to the stop sign and turn left, go about a tenth of mile and PDO will be on your right. Don't know if they have a US phone, the wife takes care of that. They have a website!
Odds are the seller will live in the states, Arizona most likely, so you can meet there for final payment. I would bring along a cashier's check, enough to make a meaningful deposit. Be sure the person you are dealing with actually owns the RV. If you see something you like have the current owner set it up and run all the systems . AC, fridge, heat, electrical appliances and lights.
Again, I say better to buy in Arizona and have someone haul it down. If an RV has been here for years it might be in really bad condition. the odds are not good finding a nice one here. If its a good one they will take it to Az to sell. If it's been sitting around here for years they will dump it. here. Locals are concerned more about cost than condition.
That might happen but if it is a nice one it will not be easy to sell here. Geoff at Boarder Movers will bring it down from AZ if you buy one there. Probabaly other also. Bringing it across is not a big deal. Just do not say you are leaving it in Mexico !!