A pulley should not cost 150 bucks. Seriously. Talk about price-gouging. I think the tensioner pulley would squeal more than it would grind, anyway? I know my idler pulley did, I wouldn't think it would be much different.
Let me see if I can find the FAQ for a coupler fix.
Edit: Found it.
http://www3.sympatico.ca/aepa/blowerinstall.html