Thanks. Do you think I'd have much luck auctioning it here? I don't really have much of a reputation. At least with EBAY there are some guarantees and protections for the buyer. I sold a lot of miniatures and gaming items online from 2005 - 2007 but those websites aren't around anymore for references. Other than EBAY at least.
I feel like your opinion is that access to the pledge manager is a significant value, so no, selling here probably won't net you what you'd like.
There are a number of people on these forums who are willing to piggy-back others' orders with their pledge manager access, so having access of one's own isn't too valuable a commodity here.
And of course you can visit the Myth game page to see what other people are asking for it on the Marketplace and see if that meets your expectations. You can drill down to see what it's actually sold for as well.