I could understand when Fred was the only one out there and he had the spacers for $365 and you could find a much cheaper quality alternative on ebay for $160. I could see folks taking that risk, it a was $200 difference.
Having a vendor that Mark uses which appears to be similar quality of a Fred spacer (top of the line alloy, hub and wheel centric options) for ~$210, I don't see taking that risk for $50. It's worth the $50 not to have to grind off the studs!
When I need new tires, I plan to get spacers and if I don't find a used set of "Mark's" spacers in the classifieds I plan to get them from Mark and I know I am one of the biggest tightwads on the board!