Vagabond - have you ever run a coffee shop?
I would say Costco maybe a good option as a lot of businesses use them for supplies.
Could you bake in-house, not sure of the health regulations but if you had fresh muffins coming out of the oven I think customers would like it. It brings back memories of going to a BB and waking up to fresh warm muffins. Starbucks doesn't even do fresh baking. It could be a differentiating factor.
If you had a couple of PCs with Interenet connections with free use could bring in some traffic. Another idea is to have an artist hang up their art for 3-4 week period and get a commision on it.