Purchasing a car for travel

Has anyone ever purchased a used car for the purposes of extended travel?

What was your experience? Anyone want to recommend a vehicle that runs well even when it’s old? I’m thinking along the lines of US$3,500 or so for budget. Buy it, use it to travel for three or four months, then resell it. Is this the best route, or is a rental a better way to go?

VWs beetles.

A lot of long term travellers in Oz buy a car from a dealer and tell them that in x weeks/months whatever time they will no longer need it. The dealer then agrees to buy the car back at an agreed to price (with a list of other provisos as well I imagine - such as km’s travelled, condition of car etc)