First time sail boat buyer
The above comments are valid and good. However, I always recommend to new, potential sailors that they first purchase a very small sailboat, something like a Sunfish, Laser or other boat of similar design. The reason is that you get a much better understanding of how the wind and water interact. On a keelboat, the first time buyer would not be tuned to the subtle nuances of the wind and the water. The knowledge gained in sailing a small boat (even if you only sail a few months on it) can be transferred to sailing a keelboat; but it is more difficult to pick up the subtlies from a keelboat.
Consider a cheap small boat as a sacrificial learning expense. You might be better off. Anyway, good luck with whatever you decide.