Being between Scylla and Charybdis is an idiom deriving from Greek mythology. Several other idioms, such as "on the horns of a dilemma", "between the devil and the deep blue sea", and "between a rock and a hard place" express the same meaning of "having to choose between two evils".
Dealer number 1 gives dealer number 2 a coin on consignment. Dealer number 2 chases me down on the bourse floor to show it to me and asks "Are you interested?" I buy the coin. The 1799 dollar which I brag about. Turns out, dealer number 1 would have sold it to me as well. But wait! This is not the sticky part.
Dealer number 1 asks me, "How much did you pay?" I tell him: $xxxx.xx. Dealer number 1 then tells me that dealer number 2 told him that I paid $xxxx.xx MINUS $100! I guess that there is no honor among thieves.
As both of the dealers have become my "go to" guys I felt quite annoyed with this. Actually I was sick to my stomach. But I did not want to burn any bridges.
Saw them both last Sunday. Again all three of us together towards closing time. After two months I have gotten over the nausea over this affair.
I am watching both of them more closely. I was never unhappy with the purchase. Only the lying between so-called comrades in the business.
If by 'on consignment' you mean dealer 2 cheated dealer 1 out of some profit, that's quite dishonest. Otherwise if it's just fibbing about the price, it's dishonest but less deplorable. Either way dealer 2 seems to be the one worth being wary of.
Some back story: Dealer number 1 allowed me to keep his complete Barber, aka "V" nickel set overnight in my hotel room last September in Manchester, NH. The next day, I bought three of them - trust between seller and buyer. Dealer number 2 routinely lets me go through his box of "Just bought, not re-priced" coins. Both give me decent deals. I am beyond feeling caught. Just do not like lying among dealers. But I suppose this is to be expected.