What's Technics SL-1200MK2 worth?

Amazon has them for $1325. They command premium prices in certain circles. As an aside, I think the Denon 103 MC cartridge is a good match for that arm. Enjoy.

Consider the missing headshell a good thing and don't scrimp on the replacement. Get one (or more) of these. The ZuPreme headshell is a more solid mount, adds some effective mass to the tonearm for a wider variety of cartridges, has higher quality lead wires, and has adjustable azimuth. I consider this headshell to be the first step in getting better performance from the SL12x0 series.

I like Audio Technica carts with the 1200/1210. You either love 'em or hate 'em, however. Some find them too bright, I don't.