I got mine from LciPaper. It was around $50 when it was shipped. But that was for a ream of 500. It was 17lb weight.
http://www.lcipaper.com/GNRC1711_CTN.html
They also have a 29lb weight as well that's more expensive.
http://www.lcipaper.com/GN2911_CTN.html
It works wonderful in my laser printer. I'm very pleased with it.