ATM Source for grinding polishing compounds?

[Ari <Ari@birmingham-us.crosswinds.net>]

I recently mailed Newport Glass to find out various costs, and the
result surprised me. The enhanced coating cost more than the 8" plate
glass blank by $15, for example. What really got me was the cost of the
grinding and polishing compounds and pitch:

80SC1L  $8.00   - #80 silicon carbide, 1 LB.           
120SC8Z $8.00   - #120 silicon carbide, 8 oz.
180SC8Z $8.00   - #180 silicon carbide, 8 oz.
220SC8Z $8.00   - #220 silicon carbide, 8 oz.
25AO4Z  $6.00   - #25 aluminum oxide, 4 oz.
20AO4Z  $6.00   - #20 aluminum oxide, 4 oz.
15AO4Z  $6.00   - #15 aluminum oxide, 4 oz.
9AO4Z   $6.00   - #9 aluminum oxide, 4 oz.
CO4Z    $8.95   - cerium oxide, 4 oz.
BPM1L   $9.75   - medium burgundy polishing pitch, 1 LB.

That's $$$74.70!!! Does anybody have a cheaper source that would ship,
an equal price is ok for greater quantities.

Thanks,
Ari Friedman
        There's light at the end of the Sonotube.