Nehuge,
You supplied no background, but the way you phrase this leads me to believe that your wrench skill is well above Yellow Canary. It may even be weekend good wrench, but what ever. Think about this, you are literate, you write like you have an IQ over 85, and that may put you ahead of the guy that gets the job when you go to a shop.
AND
You have a very vested interest in getting the whole job done right. So, if something isn't as good as it could be, you can hold up and get it right.
For 3K$us, you can buy the book(s), tools and all the parts, and when you get done, you will know more and have more confidence in the coach. That is worth more than good tires....
Speaking of tires, I'm not going to, but that brings up rubber. Your coach is not all that old (from my POV). But 25 years is plenty for all the rubber parts to age out. Not just the hoses and belt that you have mentioned, but also the fuel lines and flexible brake lines, and the brake fluid should be flushed if you don't know when it was done last. The brake fluid is good to do when you have done the brake lines as it will have to be replaced then.
Remember: The big mistake that most home mechanics make is not taking enough apart to get things as they should be. You are not getting paid or charged by the hour, and you don't (I hope) need it to go to work Monday morning. (Where is my BTDT hat...)
Yes, take lots of pictures. Get a camera that does that well (part of the 3k you are not out of pocket).
Now, you are in Arizona. If that is where the coach has lived, rust will not be a big issue, but if it was on the gulf coast (a week might do) you will have to deal with it. Patience is the biggest advantage here. (Says a guy that has always lived where they use fender solvent to clean the roads.) If things don't loosen, soak them over night and try again. Anything you don't brake, you don't have to replace.
Why did they quote 3K$?? Because the shop manager looked in the flat rate book and added up all the hours for each job. => Individually!!!
So, my vote is go for it if you have the confidence in your own capability.
Matt
