I hate to show my ignorance (not that it's possible to hide it) but is Pismo a separate brand, or is it an Apple product?
Sounds like it is a good deal -- I would buy a Pismo for $6-800, if it will allow me to do the same as iMovie? (I don't have iMovie yet, but I think I would want it on my next Mac).
There was a string about eBay, though, and I am personally very leery about buying a computer off eBay, escrow or not.