It's one of those questions, Com_VC, that's hard to answer without knowing the layout of your garage and so on. In my case a local electrician installed it for $500, but I supplied the outlet and so on. We already had three phase wire to the board, and the electricity people didn't charge anything to install the metres.
You're on the right track though. The three phase tools and welders are relatively cheap and better.
If I were you I'd start shopping on Ebay for outlets and a three phase circuit breaker.
Good luck.