After reading your original post several times, I just realized that you are not asking about a particular boat, but several different possible scenarios. My advice based on what you have shared.....
It's a seller's market. Good boats and good deals sell quickly, so don't drag your feet if you find a boat you like. Make an offer, agree on a price, and schedule a survey.
A boat that needs a good cleaning is not necessarily a bad thing, but says something about how the owner cared for the boat in general. A boat owned by a meticulous owner shows in appearance, but also will be better maintained.
No used boat is really "turn-key and needs nothing". Every boat ad you read will tell you that, but in reality, the survey will uncover some things that should be addressed (and can be negotiated) and other things you will find out long after the purchase that you will have to deal with. Be prepared for both of those scenarios and budget appropriately.
The used boat market is pretty thin so you may not have a lot of boats to choose from. See what's available and start looking at them. Every boat looks great online, when you see it in person you'll know whether it's the right one for you.
Good luck in your search.
