Searching for Rusty, I found in some offers from 3 to 4(in a few I checked), some seem to have been completed outside the forum, because the posts do not have a definition; So the atual offer is valid: 45SC.
The same goes for Santa, that the last valid offer in a recent post was 1GC and 1SC, but did not see the completion of that post either. Without a consensus of brilliant value, I would say that I would not sell mine for less than 1GC, thus considering the last valid offer from Santa in that post, up to 1G, 1S, I would say that this is the value of the brilliant in this auction.
Also remembering that the auction goes until the 24th of december 23:59