Hi Ed
These are the same overall dimensions as the PL700B and Series 2 except that there is a radius on each corner that you can see in the picture instead of the sharp corner that was on the originals.
Yes, the $13 in the cost is basically the USPS medium flat rate shipping charge so if more than one set is ordered, that $13 goes away on the second through 4th set. I believe that 4 sets can be packed in that medium box.
The black oxide is a mil spec finish and the lot charge to get anything done in that finish is a killer. The copper upcharge is bad enough but the finish charge to turn them black is crazy money.
When I buy black oxide SS screws I run into the same, very high upcharge.
Gary, I ran a couple experiments using copper and aluminum heatsinks. I also was thinking that with copper heatsinks I could do away with the need for active cooling. What we found out was that copper does indeed draw heat away faster. But it still did not have enough area to keep up ....