I checked and there arent any on kingsnake, but here is the site, may come in useful in the future.
http://market.kingsnake.com/index.php?cat=32
As for cost, really everyone sets their own, but I go with CU because Mike keeps that nice, handy list, and sells them at that cost. he even has one up for sale right now.
Oh, and as for it being less than a Pewter, it seems Fires havent been played with much until lately, and because of this morphs with that gene will likely be more expensive since the combos are fairly new.
Oh, and the morph list states that Pewters were first produced in '03, making them a fairly old morph at this point.