Your coin is a very nice atheist
Cud, but from the pics looks AU and not MS (not dissing your coin, it's great, but talking about a value thing). Similar coins have sold recently for around $55, although yours is a shade larger than those. $75 seems like top dollar for the coin, so if that's what you want why not just list it as a BIN? Putting something up at auction with the starting bid the likely highest possible ending bid seems a bit against the idea of an auction, which allows multiple buyers to have at it and set the high price competitively.
Generally
Cuds like yours have been selling very well, but approaching Christmas I expect prices to fall. Who buys a
Cud for their kid at Christmas? Generally people spend less on custom coins and put their money into more traditional Christmas items. And yes, lots of people sell coins before Christmas to raise some money to buy those traditional items (and take rolled coins to the bank if you are someone looking for customer wrapped coins) so the market actually gets a bit depressed by the additional items for sale.
Just an opinion, but I've sold a ton of
Cuds over the years so have experience with them.