Issued uniforms will make up the bulk of that cost. Unless you're currently enlisted and bring some items that could crossover (ie. I'm bringing my NWU parka and fleece. It's quite expensive. I'm in Hawaii so mine is pretty much brand new still.), you won't be able to bring anything that would take off a substantial amount of money. You could bring t-shirts, socks, etc, I guess. You will be getting paid during OCS and will also receive a decent initial uniform allowance. The allowance won't cover every, but it will definitely help.