In all seriousness, I buy tools every time I flip a bike for profit. That doesn't figure into the profit/ loss column in any way. The best buy I ever made ( a long time ago) was a Shimano 4 piece tool set for head and BB (fits most Campy) and a chain whip, along with good cone wrenches(old Park).

After 20+ years they don't owe me much, but I use them all the time. Tools are usually cheaper on the street than on eBay.

A work stand is also much better than ropes off the ceiling, IMHO---but nothing beats a good set of BB & head tools.

Just remember, good tools last forever, and a good bike can make you live forever, or at least enjoy each minute you live!