This is not one the OP is talking about at all. What he was asking is lets say we sell a bag of weed for 410 bucks. And right now a Btc is worth $10 bucks.... then the bag cost 1 Btc. Well if the Btc go's to being worth $20 do we still ask 1 Btc that is now worth $20 so we are selling the same bag for $20 instead of $10...or do we sell for .5 Btc making it still $10? This example should make it clear to everyone... 99.999% of us base our prices on the dollar not the Btc.. So it makes no difference what the Btc is..You will always pay the same. Yes you can find one vendor that just charges 5 Btc regardless of the value of it..But that vendor is usually a moron and just does not understand the Btc. But all of the solid vendors price our items in dollars..So you never have to worry. Silk Road takes a 24 hour waited average from Mt.Gox for the value of a Btc. I would suggest you selling Btc charge SR value not the Mt.Gox price. Your customers will be happier and it will be a lot faster and easier for you to get the Btc to your customer as you can just send it to them from your SR account to theirs. That way you are not having to wait for any confirmations. On top of that your exchange rate will be a lot easier and clear to your customer. To get that price at the time of your "deal" just put an item into your cart and you will get SR current value for Btc..Then go from there. Good luck