Good find! they go for way more than that on ebay etc. They make amazing pictures, I wish they were slightly less fiddly to use tho. And also that mine stopped randomly jamming when I wind on :(
Talking bargains I got these for ¥800 (about £4.50) the other day, I only wanted the mz7 "for my girlfriend" but basically giving away Pentax SPs is the only way to get rid of them here I guess (I now have two and both came with things I wanted that were already underpriced).