I can understand having slightly out-of-date prices in a printed magazine. I cannot understand having out-of-date prices on your website. If you have to email ONE customer and say that the price isn't correct, you should change it then. This is especially true if a large amount of your business is done online. Also, if you're out of a particular size, perhaps you should go ahead and change what you're advertising.
Am I expecting too much? Is a $72 price difference or no longer available products not worth updating?