I would figure ~ 5,000 miles for that trip. (50 days)
gas @ 10 mpg & $3/ gal =
$1500
Food, simple = $10/day =
$500
not-so-simple = $1,000
eating out = $2000
lodging = $15 / night for no hookups
$650
= $40/night full hookups $2000
entertainment $80 for National Parks pass, $50/ week for sauna / hot springs... =
$350
Total econo trip = $3080. 'upgrades' = ~$1,000
Repairs are tough to calculate, but with oil / tranny change with fresh Baldwin or equiv filters & synthetic (for heat tolerance). + replace hoses and belts and rubber fuel lines. Keep a spare water pump and electric fuel pump ($20) and fuel filters. GOOD tires and wipers! Check data code on tires, they are only good for 6-7 yrs. Check muffler and exhaust for rust. I would expect no repairs, but keep a credit card handy. Hopefully you can get by W/o using it
I would also buy a 'good-sam' membership or triple A
'plus' ~$150
Maybe a discount campground membership, or use my usual resource.
Free Campgrounds for RVs
You didn't mention Wyoming, but you've GOTTA Go There !!! (coming from a Colorado kid, who escaped to WY every weekend) I like Snowy Range (Near Laramie) and rte 14 and 14a in the Bighorns (Sheridan to Lovell) and of course the Beartooth Highway & Tetons. + Devil's Tower (NE) Lots in SD too. In WY, many city parks offer free camping (Powell is one spot that is GREAT)
Some other 'must see's I've found
NE = Capital tour, Prime Rib at the Oak Tree in Malcolm, near airport (only on Friday and Sat Eve). Windmill Recreation area
Windmill State Recreation Area - Gibbon South - RecreationParks.net Pioneer Village (free admission w/ camping, last I was there, it is really great). North Platte for history. Burger in Paxston at the cafe / bar (tons of stuffed wildlife). Cabela's @ Sidney (free Camping), 'Car Henge' in Alliance.
Colo, I have many recs, since it was home for 25 yrs.
Colo Springs is worth the trip, AF Academy and Garden of the Gods., then head up to Buena Vista, and over Independence pass to Aspen.
Be sure to spend a night in the Glenwood Canyon, free, and plenty of train noise !, very nice place, but many sites are similar nearby. Glenwood Springs pool is great at evening and in early morning (even better w/ snow)
UT, I really like Arches and Bryce NP
NV - Great Basin NP is a gem (maybe the only gem..., but Valley of Fire 50 mi north of Vegas has nice camping)
CA I spend most time on the coast from SF > Crescent City. I like to eat at Samoa Cookhouse near Eureka (all-you-can-eat 'family style' at a Logging camp kitchen / great museum) Go for breakfast if they are having French toast !! (menu changes daily, call first) Another inland great in CA is Lassen NP and Lava Caves (on the way to Klamath Falls, OR)
In OR see Crater Lake, and take the rte out to the NW and down toward Roseburg, great camping spots along the river BEFORE Roseburg (A free hot springs, and pretty hike to falls also). OR coast is best between Newport and Seaside. Hug Point state wayside is a MUST SEE. Check Google images. There is a wagon road blasted in the rocks on the north side of beach, it has great tide pools on low tide. Nice caves and water falls, perfect red rock colors for sunset pics. Cannon Beach has a couple nice RV parks, I like the one on the North side near the road to Ecola SP. (No CHEAP places to stay near Cannon Beach.). Then drive into Portland and enjoy free nightly concerts in beautiful parks (be sure to see the Rose Garden, ~1500 varieties. (garden is near zoo + one in NE Portland off Rosa Parks way). Stop at Powell Books (one city block of 3 story book store), then off to Columbia Gorge and on up to St. Helen's and Rainier. Try to fit this in (free art stroll near Rainier)
Dan Klennert's Spirits of Iron
Olympic Peninsula is great with Rain Forest + ferries are free eastbound on your way top Seattle (for passengers). Depart from Bremerton or Poulsbo (nice little German town). North Cascades is nice rte. See the Laser Light Show at Coulee Dam. (Army Corp has NICE campgrounds in many areas)
RV Camping at USACE/COE US Army Corps of Engineers Campgrounds
too many places, too little time.
For a vehicle If you are single, I would consider a conversion van (Roadtrek is nice, as well as Pleasureway ...) I've used many a VW van, but having a toilet is a plus (at my age now). I think the best deal is to find a used DHL Sprinter and convert it to camper. These get 25mpg on Diesel and drive NICE.
I currently use a Rialta
Rialta Heaven - Home. ~17-21 mpg, full Class C. genset, shower (nice outdoor one too), microwave, sleeps 4 rides 8. These have a weakness in high tranny temp, so need a $90 cooler (or a $5,000 tranny every 50,000 miles... VW says it is a 'lifetime' tranny, and it doesn't even have a dipstick!!, but those in the know change fluid frequently, as it runs at 250F +)
While camping is OK, I really prefer to use my 52 mpg Diesel Passat wagon and stay in private Guest homes (~$10-$20 / night). I enjoy the info I get from the hosts, and they are often very well traveled and full of great ideas. They are super when traveling overseas. (one directory I use in USA is largely farmers and that is great for activities and helping out + quiet sleeping & FREE place to park camper).
2 of us did a 12 wk / 12,000 mile trip for $2000 total quite a few yrs ago. (40 mpg car w/ bicycles on top, and tent in the rear, cookstove close at hand (we were
freezing camping in Canada in October). Washington DC was like the tropics when we finally got south. Lots of bike trails there, we spent 3 weeks at that stop!