@Thomas Good Sorry for the delay in reply.
To see c-stores at that price is not uncommon. In my area prices are anywhere from 200k-2 or 3 Million.
Are you buying the business, land, and inventory? Or are you buying the business and leasing back the property?
I am not familiar with above ground tanks. As far as sales being around 2 mil that is common for C-stores aswell. I would ask the owner if they are interested in Owner financing at least a portion or price of the "down payment".
To really get an accurate net income, look strongly into the Cost of Inventory and the Labor. Those are the two big things that will make or break a C-store. If you can stay on top of those with an iron fist you can make decent money with C-stores.
Gas stations with Food services are not for the faint of heart. They require a lot of time. Being an absent C-store owner is not a route I would recommend. Although I am a Real Estate investor and work for a family that has multiple commercial real estate properties, 99% of my time is involved with our C-store.
Hope this helps.