How to update item prices in a Bricklink store?
The easiest way is to download and install Brickstock (www.patrickbrans.com is the site it is located on AFAIK), pay for the upgrade to the full version ($20 via paypal) and then download your entire store inventory, do ctrl-A ctrl-G which downloads the current prices, and use the “update inventory in bricklink” option from the File menu to set the new prices.