Go to the store, fill out all the details, other than the credit card, including shipping. That will give you a tally of what you should expect to pay. Print the page out, then send a money order to the office for the amount you're given. Address the envelope to Bob. He's done this before, so I don't see why he wouldn't do it again - just drop him a PM before you do, to confirm. That way, no credit card information has to be passed over.