What they do is scour the US for prime used cars and then buy them, then mark them up about $10k.
I recently saw an E39 M5 on sale at the M5 board asking $26k. EAG snapped it up really quick and then put it on their website for $36k.
I view them as the place I'll go when I win the lottery, and want a primo classic BMW and don't care about the price. I think that's probably their customers, people with more money than time to search for a really good car.
"When you were born, you cried and the world rejoiced. Live your life so that when you die, the world cries and you rejoice." - Cherokee Expression