Hi Patrick, Welcome to the list. Depending on your future plans for bodies there are some good deals out there. If you plan to get a newer autofocus body or the (hopefully) soon to be released digital SLR you should look for either A series (non-autofocus) or F and FA series (autofocus) Pentax lenses. There are metering and other compatibility problems with older Pentax lenses and most of the newer bodies. If you have no plans to get an autofocus body then there are some great deals on older K and M series lenses.
I was in a similar situation when I joined the list, having an ME super, M 50/2 lens and a bad Vivitar 80-210 lens. I bought a K 28/3.5, M 135/3.5, and an M 200/4.0 for $225 from KEH (highly recommended on this list). My ME super died and I got a K 1000 with another M 50/2 and an M 100/4.0 macro for $160 off e-bay. I have since made a few other purchases upon recommendation from the list. Besides the lenses listed above (all highly recommended) the K 35/3.5 is legendary, if you can find one. For a longer lens the F or FA 300/4.5 is an astounding lens that you can sometimes find under $300. Even though it's an autofocus lens it works fine manually. The list is sometimes too good with equipment enabling <VBG>. Butch Each man had only one genuine vocation - to find the way to himself. Hermann Hess (Demian)