I dont think there are any of them out there that people are willing to sell, however I have a 7 Digit made in 2005 if you want that? It also has Counter Strike and Counter Strike: Condition Zero on it.
It depends really. I've seen 4 digits go for 50-70, 3 digits for 140-180, and 2 digits for 500-1000 but it all depends on the seller and the games on the account too.