I've spent a few quid on bit's and pieces, shoe's, shorts, tech t's etc and the odd massage here and there. All of these have made a contribution to me being faster now than I was with the kit I had when I started running. The biggest difference is my body which I've spent many hours training. (Think about the food spend for that amount of calories!)
If I paid for a guranteed faster time I would always know I had......