My usual method of grocery shopping is to map out the best sales at about 5 different stores and then go to 1 or 2 a day that week. I decided I needed a price book with local prices so I could check where I want to pick up x item if it's not on sale, but also to find out if the sale price on x is actually the best deal.
So I've created a google document that I want to share, a Price Book. It's very sparse right now, but I'll be adding to it as often as I can with all my shopping trips. If you're local and you want to submit some prices that you're aware of from your shopping trips to help flesh out the Price Book, send me an email at email@example.com. Also, if you have an item you'd like a "price check" on to be added to the Price Book, send an email to the same place.