Nit: you're not available in my area (27605), and you made me enter my email to find that out. If this wasn't a YC company I was curious about, I would have bounced.
On one hand, its true that certain places are known for good deals for certain items. If there is a specific cleaner I buy for my house, it doesn't matter which store it comes from as long as it's the cheapest.
But food is different. I'm more concerned about quality, shelf life, ease of shopping experience, and availability. There's probably a reason why strawberries at CVS cost $1 vs $3-$5 at Whole Foods. However, if there is a Farmers Market 2 days later and they sell strawberries for $5 - $10, I'd hold out and pay the higher price because I want to support the community and I know the strawberries might actually be better.
Maybe there is a way you can tap into the social consciousness. For example, my mom is very proud of her ability to compromise quality and price. She will tell me something like "go Safeway to buy bread items, but go to Nob Hill if you want meats".
If we don't have data for your zipcode, then we don't send you email. We just keep your address on file so we can notify you when we launch in your area.
Suggesting recipes that use deeply discounted items is a good idea.