The Casio MQ1 calculator is used prominently on the Gauntlet keypad, as the Helmet Keyslot circuuit board, and the battery cover is also moulded into a gauntlet. Prices have now reached in excess of £200 for a piece once in the £80 region.
Prices are out of hand for a lot of found parts, which i attribute mainly to greed.Nowadays it is around 250$ to 300$ range. Working or non working. A good one with box could be around 350$. The chip alone for the back of the helmet is around 100$ to 150$ if someone want to part with it.