I have a 1994 georgie boy pursuit 28' class A on the chevy P30 chassis and the 454 with 4 speed transmission. I got it in decent shape and in the last 6 months I have sunk a ton of time and money into it trying to make it right. Here is the list of things I have replaced, and what it cost me:
Roof A/C unit, dometic 13.5 BTU $600
Roof materials, coating, caulking, etc $300
Used tires from craigslist, enough to get me by for a year or two $450 plus $140 to install.
Front airbags inside the coil springs $100
All 4 new shocks $100
Generator service(oil, filter) $20
New carpet and vinyl flooring/trim, etc. $500
Water pump, 3 belts, thermostat, all new heater hoses & clamps, radiator cap, radiator flush and new fluid, engine oil & filter $300
Expansion valve, multi switch, pressure switch, new a/c hose, receiver/dryer(all for the dash a/c system, $175
Charge the dash a/c to test for leaks $153
Plus, I built a new trailer hitch and spare tire carrier. The list I just put together does not include any of the labor which I did 100% myself. If I would have had someone do all the work, it would have easily been $5k, maybe more. The RV as it sits is probably only worth about $8k. But now, it's exactly what I want, it's paid off and works for us. The 454 has enough power to get the job done, and the auto tranny's since about 1993 have gotten a lot better. They used to use the TH400 which was just a 3 speed and notorious for leaving motorhomes stranded. Back in the 80's, we had the same style class A and went through 3 transmissions in about 10 years. The P30 chassis is less than desirable, it's not built heavy enough to carry the weight of a big motorhome. On a smaller 30' or less without slides, it should be just fine. All motorhomes are gas hogs, none of them will get the mileage of a prius. Mine gets about 9mpg with no headwind and about 7 pushing a ton of headwind with a heavy trailer. Just look over whatever you get very carefully, have a mechanic check it out. If it is still on the original water pump, hoses, roof air, you need to budget that into the total amount you will spend. These things are money pits.
1999 Holiday Rambler Endeavor 38'. Cummins ISB 275, allison 3060.
Toys pulled: 22x8.5 open deck PJ flatbed. 5200# axles. Sand car with ecotec engine. Multiple 1980's ATC's(3 wheelers). We're duners!