I don't need to but I would like to. Mostly just because it's interesting but it does serve a practical purpose too. It lets me know if the shop is lying(which they almost always are) when they say that they can't match a price. If I have stuff I need it means I can walk into a shop with a list of parts and the price I'm willing to pay for them knowing that both of us are going to be doing well on the deal. Otherwise I get stuck giving them a list, getting quoted a ridiculous price and spending the next half hour haggling only to end up walking out and ordering the stuff elsewhere.

There is simply no reason to censor this information if people who have it are willing to post it.