It is possible to have multiple base prices in Magento but you need to set up different websites:
Step 1. In Magento product price scope can be kept either global or per website, so you can have only one base price currency for a website. To set the Catalog Price Scope to website log into the Admin and go to System – > Configuration -> Catalog -> Price
Step 2. Set up multiple websites in Configuration > Manage Stores (you will need to creat a website/view and store for your new shop)
Step 3. Set the pricing for each one in Configuration > {switch store} > Currency Set up

