With such a massive price jump even at MS-60, I'd say it's definitely worth the crackout gamble, and $6,100 is a pretty good price for a 58. Don't you think that the dealer has already tried the crack out game a couple of times though? I don't see any obvious wear on the coin in your images, but light circulation wear on a double eagle really tends to stick out like a sore thumb when held at an angle. Either it has wear and is legitimately a 58, or it doesn't and should be a 63 or 64.
Tough call for a rare-in-grade but demand-limited issue. Dealer doesn't have a safe profit guaranteed - average sale including the vig for the 5 sold in 2017: $5957.40, but with two outliers and three much lower. Your coin would have to substantially beat those three of five at Heritage for you to realize $6100 from that sale. Only 7 out of 19 going back to January 2015 (14 Heritage, 4 Stacks, 1 Ebay, both major TPG's) sold for enough to give you that return (figuring the current 20% juice). This one boils down to your risk tolerance, I think. Me, if I'm comfortably in the black at that number, I flip it to the dealer and let him take the risk.
