This topic is pretty common on these forums and you see many of the same answers.
The people here have no regrets. Those that did sold the RV and moved on.
Go to RV shows and get as much time in various rigs as possible. Sit in each of them for a good long time. Imagine living in it. Imagine sitting there watching TV (or whatever it is you do - sew, knit, carve, read, etc.). Is there enough room for your clothes? Is there enough storage in the basement for all the things you plan to take? With the slides in, can you access what you need? Is it big enough? Only you can answer that.
You typically get what you pay for. Very cheap is usually very cheap (pressboard cabinets, low quality components, etc.). There are exceptions, of course. Sometimes cheap is ok (e.g. weekend use) but for full-timing it is nice for the rig to hold together for many years.
Everyone has an opinion about what type of rig is "best". You just need to go sit in all of them and consider how you are going to use it. Maybe go watch a variety of rigs setup/take-down. Some rigs are VERY easy, some take a bit more effort - whether or not that matters is up to you. My coach is six buttons to level, deploy all slides, and deploy awning. I see some folks crawling around on the ground, manually setting up scissor jacks, driving back and forth on boards, etc. I don't want to do all that but some folks don't mind. Obviously, there is a cost associated with convenience. There is no right or wrong, just what YOU want.
Deciding what "type" of camping you plan to do will also be helpful. Every night in a campground with full hookups or boondocking? Will you be cruising logging roads looking for a good spot or will you never leave the pavement?
Good luck!
