For what it's worth I just requested a quote, via email, from Duke at DF Countryman for 8 CG-1500's. He came back with a cost of $11.50 per unit and $35 shipping. This puts it just under $16 per panel. The quote I got seems to be higher than some other people have been reporting in this thread, but maybe his costs have gone up since those initial orders.
In the grand scheme of what we spend on equipment for this little hobby we enjoy, I'm not going to sweat a few dollars on the enclosures. I'll probably just go with this quote from DFC.
BTW, they have an 800 number: 800-326-6820.
-Mike