If you are an elite touring pro making a lot of money, you want consistent, matched rackets customized to your liking. In that case, P1 is well worth the cost. For a club player, it would be silly to spend that much.
I do all my own customization. Aside from molding my own grip pallets, I can do pretty much the same things the pro customizers do and I work a lot cheaper.
Well said.. along with what Fuji said. Most folks can do 99% of the custom work in thier family room. Take some time..be careful and be willing to make a few mistakes. TW has a wonderful area to address doing custom work.