I have come to the realization that owning a free sailboat is very expensive!
A "free boat" is never really free, unless it was factory new, and even then you will get a bill for the sales tax and the IRS will take their 35% as gift tax...
But here it is; if you know boats, really know boats, or hire a qualified marine surveyor (that knows sailboats) you can do a fairly detailed assessment on what will be needed to get your "New2U Freebie" up to snuff.
Here is another thing to consider; what is your personal definition of "up to snuff"?
Are you looking for a restoration, or do you just want to get out and do some day-sailing, and aren't totally concerned with the "finer things", I personally am a perfectionist, so a clunker won't do it for me.
Another thing is what type of sailboat are you looking at; is it an under 20' day-sailor on a trailer with minimal rigging and accessories, or is it a 30 plus footer with a diesel that is seized, bad sails, worn rigging, and a torn up interior.
I've picked up many free or inexpensive boats in my time and depending on my intentions, I have mostly done OK; for example, I have picked up several 14-18 foot day sailor or race boats and had fun with them with minimal work, and then turned around and sold them. I picked up a 27' boat with a solid hull and good rigging with no engine, electrical or interior, the deck was soft and basically was a shell with very good rigging and sails and winches. I tore out the remaining interior and removed the deck, I (with some help) de-masted the boat and removed the cabin top and most of the deck and rebuilt it as a flat-top racer. It required some marine plywood (mostly yard scraps) and four months of long weekends to turn this into a bare bones racer.
Now if you lets say, pick up an older Hunter 30' and it needs to have the bottom peeled, the deck replaced, new sails, electrical and plumbing, engine and tanks, etc, you would be far better off seeking a vessel (at a price) that doesn't need but a good cleaning or at most a small amount of repairs.
I have a friend that just picked up a so called "bargain" 28 footer that is a total basket case, I informed him that he should have passed on it but he is determined to never get in the water. This piece of crap needs everything, and I really mean everything. In my estimation it would be cheaper to buy a 2 year old boat that needs a wash down and can go sailing, then to spend upwards of 20k and over a year of full time restoration to get what was never a really good boat (a 70's Buccaneer 28) not a single thing on the boat is really usable without either significant repairs or replacement.
You must decide if you have the knowledge, time, place, as you really don't want to have to pay yard rent while you tackle any rebuild project, and ALL of the necessary finances to tackle a project before taking ownership of someone else's dead project.
Good luck and smooth sailing,
Capt. Bob
Owner of a 1993 Hunter 42 Passage
Prior owner of: Pearson 30; Hunter 19, 23, 30 & 36; Catalina Capri 14.2 & 27; multiple Laser's, Sunfishes, and a verity of other boats (over 30 different makes, models and sizes)