2000 Mercury Sable EGR Valve VS Fuel Pump

I have a car that had not been driven for months. Prior to not using, car would cut off after starting unless gave some gas. Once car warmed up would stay running with no problems. Had to start using again. Car did same thing but this time I drove to a store. When came out car started but was hesitating then cut off. Have not been able to start again. Had towed to a shop. They said it was the EGR Valve and would cost $180.00 to repair. When I got to the shop to pick the car up the guy said it wasn't the EGR Valve it was the Fuel Pump. I asked how he could not know that if he did the diagnostic check on the car. He said the check didn't show which one it was just that the problem was with the fuel system. I am a female and I get the impression I'm getting screwed. Does this sound right to you? Could you possibly give me an estimate of what it would cost to replace a fuel pump? Also where is the fuel pump located on this type vehicle? Can it be accessed from under the seats or does the car have to be on a lift, and the fuel tank removed?