We purchased a 2007 Dutch Star (4037) used and have done several modifications to make it more suited to our "style". We have not regretted doing ANY of them. We are fairly experienced Class A MH owners, but never bought a used one before. I am a 63 year old woman and did the work myself - except when lifting frig in and out of RV. Here are the key mods that we handled ourselves:
1. Replaced TV's with new LED's. Added cabinet storage behind bedroom TV.
2. Replaced Norcold with Samsung 197 - would never have a Norcold or Dometic again.
3. Replace kitchen faucet with higher one. Added under sink ceramic water filter. Added soap dispenser. Reworked under sink for better storage (also removed subwoofer.) Also replaced both bathroom faucets with upgraded ones.
4. Added solar to roof (this one I did NOT do myself) with remote digital controller.
5. Added power water reel.
6. Added Sanicon (another of my "must-haves")
7. Changed exterior shower to utility faucet
8. Installed MCD Duo shades in the cockpit (salon and bedroom next year) They are easy to insall and the company is very helpful with measurements and tech support.
9. Added "360" vents on roof tank vent pipes.
10. Resealed roof.
11. Installed Rand McNally Xite Infotainment System (XSG2NA-X1 7 inch) with RV specific GPS/Sirius/Changes the baby). Added comp wires to front TV for easy passenger viewing of navigation. Added additional radio speakers in valances.
12. Upgraded original Sony Home Theater with Samsung.
We have tile in the salon/kitchen, but will probably replace the carpet on the slide in the near future.
There are several other smaller changes we have done and some other large changes in the future. If I can do it, almost anyone can do it.
They all came out well and we are very happy with them.
Having said all that, I agree that you should not do anything if you are going to sell. We have gone that route on other coaches and never recouped any of the investment.
(I have not posted my mods yet. Too busy doing them. But if you want pix or details, let me know.)