2002 TL-S remote & key

I lost my main set of keys over the weekend and saw that there are a bunch of people selling their old remote fobs on eBay. Does anyone know how safe it is to buy these secondhand and program them yourself to work w/ your particular vehicle? The dealership told me it would be $60 to copy and program the key alone and another $100 for the remote.

Any suggestions to cut costs (if at all possible) are greatly appreciated!!