There are a lot of RV'ers in your situation... I am probably 20 years from retirement, and my kids are all school-age now but we started RV'ing 11 years ago when we had two toddlers. And added another baby (who is now 8yo) along the way, just for fun.
We have always been weekend/vacation type campers. Maybe my wife and I will look into the part-timer or snowbirding gigs in 20 years!
The way I (and many others) mitigate the high cost of buying a new RV, is to not buy a new RV. Gently used from a private party (after TONS of research and knowing exactly what you are buying) is how to get into this pastime with your wallet still intact. Experience and willingness to learn (which you seem to have) are how you continue in RV ownership while keeping said wallet, because you will learn how to fix a lot of small items yourself and buy replacement parts as cheap as possible. Regular participation in community resources like this forum (the best one, in my humble opinion
) are the absolute best place for that. I have learned so much since joining here in 2006 that it's hard to quantify.
Renting is a tough subject. I like the idea for the income potential, but don't like the idea for all the reasons others mentioned here. I paid cash for mine (gently used from a private seller of course!) and trailers depreciate a lot slower, so I don't feel any particular pressure to "make the payments" or pay myself back. Same story for our first rig, which was a 35' Class A motorhome. It was great, but despite it's size we ran out of sleeping space for our growing family... the bunkhouse trailer is a fabulous floorplan for our current family dynamic. I can see myself & wife returning to a Class A motorhome some day. Make sure you keep checking out all the options in the wonderful world of RV's!