Tankard of Autofrost (R406A) A/C refrigerant - Seattle

I'm getting people asking me what I think the price should be, so okeh: this, with a little arithmetic, tells us the going price on Fleabay recently is $33.58/pound. Assuming the tank has 19 pounds of refrigerant in it (I will weigh it), that would work out to $638. Half that price would be $319. I'd like to get $300 plus the postage, which actually doesn't look as bad as I thought it might, given that it would have to go ground service/hazmat. For example, I just looked up postage to a town in Orange County, California, and it's about $50.