IBM Mechanical Keyboard PS/2 82G2383 Clean Tested Working Model MBIN $55.00 + 15.00 US shipping (intl shipping available)
This is just over my "Great Finds" threshold, as it's not only low-priced but especially clean-looking. (I see a speck of dust or two, but no actual grime, and the cable's spotless... Was it used at all?)