Rarity doesn't automatically mean expensive. There's a reason nobody chooses a gorn, as you say. They don't want one!
If they don't WANT one, they're not going to go out of their way and pay extremely high prices for one.
See the logic there?
It's like when people post a purple console or weapon on the exchange for 100,000,000 ec's. Chances are that posting will expire time after time without ever being sold. Nobody wants it for that price.
Ive been wondering, i had thought you could turn in the BO's for Dil but apparently you cant? The BO's vender has a sell button but it doesn't work or isn't enabled? It is almost pointless to try and sell BO's in general, even being Blue or Purple.