Regarding the Cheoy Lee 27: high teens to low $20's. I wouldn't recommend a boat that old for a first boat though.
I say go ahead and buy a boat. Sail it. You will want to try out and change things. You can't try things on someone else's boat. You will love having your own first boat. You will have more fun and learn more on your own boat.
Look for something popular from the late 70's to mid 80's. If it sold well then it will still sell well when you go looking for the next boat, and most likely for what you paid for it. 25 to 30 ft would be a good size range considering your experience and sailing classes. Tartan 27 or 30, Pearson 30, Cape Dory 25D, 27, Bristol 30, and various Catalinas in that size range all come to mind. All should be available in the $20's. Look at as many boats as you can for a few months. Listen to your heart as well as your mind. If the Cheoy Lee still grabs you go for it. They are pretty. That's important too.