What Seakindly said.
Basically, it's going to have to be your call not knowing what you're into the boat for now and all. There are very few boats that can or should be looked at from a resale perspective unless you got the thing for next to nothing and are able to turn it around right away for a profit. So, most of us do it because we love what we do. A lot of what you're asking about (cosmetics) can be corrected with minimal dollar output. Takes more elbow grease than anything else. Just ask Macojoe. The guy's a slave to cosmetics on his boat ;D He doesn't want to be the guy down at the yacht club that has the chalked out hull. :

;D
A little gelcoat repair, a little wax, and some paint and you'll have her looking good in no time. There's really not a lot of science to that stuff. When you get to the rub rail, have a couple of friends and a 30 pack to help and start lifting weights now to get yourself ready and in shape. ;D If you don't get it pulled tight, it'll look like crap. That is unless you're going to stay with the aluminum strip like it currently has.
All in all, I'd say you're not going to be spending so much that you'll get hurt come selling time. One boat salesman once told me that fresh bottom paint (if it has a painted bottom) and a good cleaning and waxing will sell a boat every time. Small investment. If you really are thinking of selling it in the near future, I would hold off on that new motor purchase though. That's where you'll get hurt and not be able to get your money back. When I sold my last boat, I let it go with a brand new trailer that I had just bought for close to $3700.00 The sale, with the new trailer, only got me about $1500.00 more than I could have sold it for with the old trailer. Should have sold them separately but I just wanted to do it quickly.
Well, best of luck. Keep a good supply of cold beers close by, and have fun.
And don't forget, if you need detailing tips, Macojoe's the guy! 8)