Sooner or Later (a boat)???
My advice is to buy a mid-20''s size boat now and start building experience as an owner and sailor. That way your learning experiences (mistakes) are will be smaller and mostly behind you before you get into deeper water (big boats = big $$$), and you can learn more safely.
Whether the C27 in hand is the right boat is a seperate matter. I would strongly suggest you try to look at other 27s especially Catalinas before deciding on that boat. www.yachtworld.com has a long list of C27s, and they seem to run from $4-12,000 in price. Boat values vary tremendously based on the condition and equipment of a boat. Recognize that just a new engine and a new set of sails for a C27 would come close $8,000, so a less expensive boat may not be the better buy. Sometimes a boat higher boat price is only covering the cost of recent upgrade expenditures, in effect the underlying boat is free.
The fact friend needs $8,000 from his C27 doesn''t mean its worth that much. I''d get the listings for all the C27s on the market, analyze them for value and then look at a few - then you can make a more knowledgeable offer to whomever you chose to.
Even if you proceed with the friend''s boat, you still want to drop the $$$ for a through survey before you are committed. My experience - there are no such thing as a good deal in a boat - the owner always knows more than the buyer - and the most you can hope for is to actually get what you pay for.
That said, go for it, with caution.