If you check around you may be able to find a glass dealer that has some 'used' glass!
I have a bunch of curio cabinets and hutches in my sewing room that I have bought a b u n c h of glass shelves for and I lucked out and found this guy!!! He charges 50 percent less than new!! He also has new glass, but the used is fine for shelves!!
Anyway, just thought I would pass it on.