We retired in 2000. We were recreational sailors on the Great Lakes our entire working life and as kids.
After Four years retired aboard and cruising the East Coast and Bahamas we decided it was time to see some of the country from the road. It was to be a one year trip that wound up lasting nearly five. We did it as inexpensive as possible so that we could stay on the road longer.
We bought a used travel trailer. 34 feet long with two slides. Very comfortable. We also invested in a Diesel truck. All used so the high cost of something new was covered by the first owner.
We left Florida on our maiden road trip head for the West Coast. It took us a year to get there. No plans we just new some thing we wanted to see. But there was so much in between that is worth more time. We loved Texas. Whoda thunk it. I though it was barren but not. The Hill country is spectacular, San Antonio was great fun we hung around S-A for a month.
Basically if we found somewher we liked we just stayed for awhile and got to know some of the people and explore the surroundings.
The Dessert was something that again surprised us. We spend winter months hanging out in the Arizona dessert that is managed by The Bureau of Land Management.
For the next few years we were snow birds on the left coast. We migrated between Vancouver and San Diego following the sun. We toured most of the National Parks out west they are truely awesome. Glacier, being our favorite but The Grand Canyon just as spectacular. It truley amazes me when follks say yea I've seen The Canyon we were there for two hole days. Not going to make it for me we spent three weeks exploring just The Canyon.
We had a major commitmment in time but not money. The equipment was less than $50,000 which we slod for $35,000 after five years on the road.
One of the hugh cost savings for us was buying a membership to Thousand Trails. It is a camping membership that is very expensive ($9,000.00). But there is a way to do it for way less. That is to buy a used membership. We did that for about $2,500.00 and when we stopped camping we sold the membership for $2,000.00. The membership is very good for the west coast. The campgrounds are close together and there are many of them. It's not such a good deal on the east coast because there are not as many campgrounds to chose from. Basically as a member you stay for free up to Two or three weeks depending on the type membership you buy. There is also a $549.00 annual membership charge. This kind of investment is only a good deal if you are doing at least half the year in an RV. A big plus is the Thousand Trails campgrounds are far superior to normal RV camps. 50% of all the properties was dedicated to be left in the wild and undeveloped. All campgrounds had pools, usually two, one for adults one for family, tennis and pickle ball courts softball fields and usually two recreation centers one for adults only and one for families.
I probably haven't really answered your question because you talked about renting an RV. That would mean a short term trip due to the high cost. But to get your feet wet there are several companies that rent smaller Van mounted campers. And I would for sure rent it out west. Drive your car there and then pick up the RV.
Check out this web site
http://www.trailerlife.com/ and click on forums for all kind of information about RVing
Good Luck