I kind of do this type of thing on an, "if I feel like it" basis. This is the second tub I've installed in Italy, and we've done one in France, one in England, one in the Cayman Islands, and I've turned down Thailand and Lebanon.
I'm still learning, and next time I'm only offering 12 hours of my time (for 8 nights lodgings). Hey, you want me to go to home depot with you because you didn't provide the tools I specified I need to do the work, no problem, but it comes out of my 12 alloted hours
Seriously though, it's a LOT of fun. Working for a "local" you get all the inside, non-tourist info, and get to meet a lot of locals and experience more of the local style, than you'd ever get as a "normal" tourist.