Re: 1992 Wellcraft Excel 20SX
Take a half-day (or more) and read as much as you can on this forum. You'll learn a ton, and hopefully that will help you make a good decision. There are far too many "oops - I bought a rotted boat" and\or "oops - the block is cracked" types of stories. Don't become another one. Cosmetics are the last thing you should be worried about.
There are MANY threads here that can help. Whatever you do, just don't get caught up in any "I need a boat for this weekend" sort of thinking.
First off, if that boat hasn't run for 3+ years count on getting the fuel out (safely) and replacing it with known good gas. And rebuilding the carb. Don't even try to add some wonder chemical to the old gas as it will not help. Minimal replacements for that boat will include impeller, bellows, possibly ignition stuff like wires & plugs but maybe more, maybe steering cables, and the list goes on.
Second, be sure to properly evaluate the transom, stringers, floor, hull and all wooden components of the boat. Wellcrafts were getting better in the early 90's but you never know. Even a glance can help -- If the seats are shredded, or the carpet is shot, you may find that the wood supporting them is gone as well. Any spongy flooring likely means a major repair job lies ahead. Potentially so major as to cause you to scrap the entire boat. If they won't let you drill the transom & stingers (and refill the holes with epoxy) then run.
Third, the 4.3 VP isn't a bad motor... but you should have that checked properly before committing to the boat. If it won't start and run, on the water, with passengers, for a good long test ride... just walk away.
There is no such thing as a cheap boat and if you think you'll "get lucky" or that you can just plunk down anything less than about $5k (for that size boat) and have something reliable you're crazy. You'll spend that in the end, pretty much no matter what.
Now, if you're handier than your post suggests then by all means dive right in. Sorry if I'm underestimating your abilities.
If you really want to push ahead, get the seller to invest in making the boat completely seaworthy. He'll make out in the long run with a better sale price, and you'll make out by getting a boat that you know runs reasonably well. No surprises.