My opinion should be taken with a gain of salt. I am a trailer sailor so this is how I evaluate a project purchase. I have purchased and flipped seven sailboats so I have developed this philosophy through trail and error (error = cost to me)
1) I think of the hull and rigging as FREE and I am not willing to pay anything for them. I can do fiberglass and paint work... minor carpentry and I can even replace bulkheads so, I'm not that worried about cosmetic things.
2) I am paying for the quality of the sails, outboard motor and the trailer.
So if you have no intention of trailering this boat, and the sails are good, you are already into this boat for about $3500 once you add a new outboard. If you need a trailer then you are into this boat for $6,500.
Other things to consider. If you just use LED puck lights, you do not need to rewire the interior. If you are going to need electronics, you are now into this boat for $9,500. Oh and you said you need a bottom job so if you are doing that yourself, you need a haul out ($300) and paint ($300) so you are now into this boat for $10,100. If you are hiring someone to do the bottom job, you are now into this boat for $11,000.
At the $9,000 level you are already talking about buying a turn-key boat ready to sail with everything on it that you need and want. I like working on boat so I might go for it if I had a trailer to put it on and an outboard came with the deal.
For example, I paid $900 for a Mac 22 that came with five very good sails (two mains -- one light air and one with two sets of reef points -- and three head sails for various wind conditions) a very nice trailer and an older but working 10 H.P. outboard. The interior was trashed. I changed that and sailed that boat all up and down the NC outerbanks.
