I am building a website for a client that has multiple brick-and-mortar locations and I need to set up products with different prices (both retail and MAP) and quantities for each product based on the location a customer picks from the Magento site. I'm looking for advice on the best way to set this up.

For example, I have 10 physical stores that sell the same 100 products, but each product has its own pricing and quantities. I want the customer to pick a store and have Magento use the information for that store. I have the pricing and quantity information stored in a separate CSV file.

I don't know if there's an existing module someone has already created to do this, if I need to set up separate Magento stores (one for each physical store), or if I need to have something custom written.