The high cost of shipping is a problem across the industry - it is killing small busness. I feel it every time I want to mail a small package (and I'm not trying to run a business).
The Federal Germination Standard for eggplant seed seems to be 60%, so they were above the regulation by more than they indicated.
www.ct.gov/caes/lib/caes/documents/publications/bulletins/b1001.pdf
is a report from the CT Ag Experimental Station (2005) that shows germ rates on commercial eggplant seed lots (page 6) that range from 50% into the 70%s. None were spectacular.
I've had problems with low germination of eggplant seeds from several suppliers so share your pain. Sorry you had a bad experience and hope next season is better!