I wouldn't worry about parts too much. There are a lot of these
chinese copies floating around. There are also plenty of examples of
people using, for example, a grizzly riser block on a harbor freight
band saw. The bearings, motors, pullies, and other parts are also
generic enough that they could be replaced or upgraded from sources
other than grizzly. Just look at how many people are able to replace
bearings on 40 year old tools they find on ebay.

brian