They don't get $30k from the seller. Seller gives up 10% on reserve vehicles. So $150k reserve would net him $135k but considering there are probably less then (20) GNX's on Planet Earth with under a 100 miles I would say $150k might be on the low side. He could put the reserve at $180k and see what happens.
Under a 100 miles puts that GNX is a completely different class. Its the class of rich people who want collectables to add to their car collection. Im sure the guy who buys it will keep it under a 100 miles so I can see this fetching quite a bit and a place like Fleabay or even here won't even scratch the surface of potential bidders from around the world.
I guess it wouldn't hurt to place it everywhere but Fleabay will be full of scammers and the aggravation for a car of this caliber imo is not even worth it!
Big auctions BIG FEES. 18% + Fee's. Soooo $150K they get $30k . I'd work with a private party deal. Less aggravation. "Barrett-Jackson earns their money via an 8% seller's premium charged to the seller (consignor) when their car is sold. They also collect a 10% bidder's premium from the buyer once the car sells " PLUS a listing fee.