Interesting that ya guys talke about this.
Any of ya ever seen dpreview.com or some of the product market sites?
They got a price watch list of a given item, the price is shown with a mini banner and best price.
Basically it lists 4 or 5 different venders with the price, then link direct to product.
take a peep here:
http://www.dpreview.com
I have been wondering if any adult toy/novalty shops do this, it would be very useful.