I have multiple bikes, whenever I had an issue regarding needing a tool I didn't have, I just ran down to my LBS and bought a Park, not a big deal. If it was on a weekend and they were closed and I needed to ride a bike I just hopped on another, racing kind of teaches you to have more then one bike, though for quite a few years of racing I only had one, but I got lucky and never needed the extra bike, and I was in college so funds were tight.

I still believe buy as you go is the best method and you "usually" get better quality tools buying them singular rather then what you find in kits.