This is a frequently recurring question. IMHO, the answer is it depends. It depends on two primary things:
1. How much work (due diligence) you are prepared to do to assure yourself that the seller does in fact own the unit, free and clear of liens and past-due assessments. This means not only getting an estoppel letter from the resort, but also looking for judgment liens, mechanic's liens and other clouds upon a title.
2. How much are you willing to risk on your own work? If the the price is low and you believe your own research, let it ride. But if the price is high or you want someone else to bear the risk, pay the premium.