Hey man,
First of all, this would probably be useful to you-its a MtGox ticker. You enter in the cash price you want for something and, according to MtGox's current rate, it updates the price (in bitcoins) in real time (you have to hit "quote" on the message to get the html code, then you just copy and paste it into your post-you'll see where you enter the dollar amount.)
Anyways, I like that Johnson Matthey round you have. I was wondering if you'd be willing to trade it. I hand-pick all my rounds (I also do have "investment silver" though-just junk rounds that I could get for the lowest over spot. Is there any round or bar you're looking for or would like? Name a bunch and I promise I'll have at least one for you. Hopefully this interests you.