I shop for my family's groceries every week, and I couldn't tell you the price of 3/4 of what I buy. I just know what a usual weekly total looks like. If there's significant change I can usually tie it to one or two items that were special that week (or that great sale that I chose to bulk up on). I tend to just put things into buckets of $1-20, $20-100, $100-250, etc. Most things at the grocery store are in that first bucket, so while I'll grab an alternate if there's a sale on, the only prices I really pay attention to are steak/large cuts of meat.