There are a number of items that you can buy in bulk and save just tons of money. "Litespeed" type battery connectors, 4-40 screws and 1/8" diff balls. A call to a industrial electrical supply house should net you the battery connectors and thescrews and diff balls can be found at ball bearing suppliers. How much will you save? Connectors will cost about $.75 each and diff balls about $8.00 per 1000. 'Nuf said?