You are missing the most important info, how cheap are we talking and where do you get them from?Despite this obvious oversight I've nominated you for a Liebster award: Lead Rising - Liebster Questions
In answer to your question Mr Acs, their plastic Mechwarrior figures I picked up a couple of years ago on Ebay. Price wise, they start out from as little as a dollar, but the great bulk of them average out at about five dollars AUS. There are a few really expensive one's, but I didn't bother with them. Their from a game called "Dark Age", it was dropped a few years back ....much like " Heroscape". The miniatures from both these line's can be picked up quite cheaply & there is a lot of variety.Also worthy of mentioning, the rest of the "Dark Age" range would make excellent small scale Sci-fi vehicle proxies.Oh, and thanks for the Liebster :)All the best.
Ohh, I think I remember them, they were from a 'Clix style game - I didn't recognise them without the distinctive bases! I'm guessing that the ones pictures are as they come out of the box, albeit with new bases?