Here is a site I found that looks like it has pretty good prices on composites.
http://www.discountcomposite.com/
Here are some prices.
Carbon Cloth
3K 282 42" Plain Weave 197 GSM No Tracers
$12.00/ YD.
3K 8HS 42" 370 GSM Kevlar Tracers (2x6) in 150 yd. rolls
$14.00/ YD.
6K 5HS 60" 370 GSM w/ Kev.Tracers
$16.00/ YD.
3K 4HS 36" & 42" T300 196 GSM No Tracers
$14.50/ YD.
3K 5HS 49" 285 GSM Glass Tracers
$14.50/ YD.
12K Plain Weave 42" 197 GSM Glass Tracers
$10.00/ YD.
12K Plain Weave 42" 197 GSM GC 31E Sizing w/ Glass Tracers
$10.00/ YD.
12K 2x2 50" 675 GSM G34-700 No Tracers
$15.00/ YD.