When I was wheeling/ dealing and buying these reserves, a lot of them moved in an out of my inventory all the time so honestly what i did was just have a notepad open and constantly updated the cost, uses left, or where I got them from if it had any special rules to it. We used forge playing this and I used the player personal notes and team shared inventory at first but sometimes forge just gets bogged down and chugs and little things like a 1 time use little bitty is best to have on a notepad, used and removed easy peazy.