Here are some links for those AB and Cycle backed cards

Cobb AB

http://www.robertedwardauctions.com/.../2006/239.html

Normal grade 6 Cobb

http://www.robertedwardauctions.com/.../2008/408.html

Cycle backed Joss

http://www.goodwinandco.com/LotDetail.aspx?lotid=12044

Normal Joss

PSA 4 for $1247, SGC 4 for $975.

heres a blank backed Cobb

http://www.robertedwardauctions.com/.../2009/316.html

So where are the premiums. there are none. The data shows this and this was a quick 10 min search and to type this.