I have heard that do-it-yourself microdermabrasion is just as effective as the machine at the astheticians, plus no sucking at your skin with the home version (read this in a plastic surgery online mag, not from the infomercial). If scrubbing your own face with some grains works just as well as the machines, I must say I don't trust either method. I've had the in office microdermabrasion (only twice) and got results similar to exfoliating, but with more irritation. Yeah I didn't go the whole 6 sessions, but I really wasn't liking it.
So I guess what I'm saying is, give the infomercial one a try but don't expect great results from any microdermabrasion treatment. In my opinion it's a lot of hype.