The Lansing State Journal has put together a list of 5 marked-up retail categories to be aware of when you’re making purchasing decisions, most of which you hopefully already know. If you can’t find wholesale sources or DIY replacements, then at least make sure you do a lot of comparison shopping to get the best deal.

We received an email from Guitar Center’s Chief Marketing Officer this afternoon letting us know that the $100 markup on their iPods was a pricing mistake, and that they’re automatically refunding the difference to anyone who bought at the wrong price as well as giving them $10 gift cards.

An alert reader noticed that something looked fishy on the Sam’s Club order screen when he was ordering new checks—if you decide to order double the number of checks, your price-per-box magically goes up the tiniest bit. We figure the amount is so small that most people don’t even notice it, or they notice it but figure they’ll still save time and shipping so it’s worth the 3-5 cents extra. Still, it’s a sneaky thing for a bulk discount store to do.