I'm wondering if the roadside guy was right.

Hello there fellow Saabbers.

My name is Mathew Wilson. I recently bought a 2001 Saab 9-3 hatchback. It had 185,000 km on it and other then needing new brake pads the car was and is in awesome shape! The previous owner really took good care of this car. I have been driving it now for over two months and I have to say it is the best car I've ever owned! Unfortunately, the other day it just didn't want to start. I tried and tried until I killed the battery. When my roadside got there and tried to give me a boost, it still did not start the car. He climbed under the car and started to bang on the gas tank with a rubber mallet, while I turned the engine over. It started. He told me he thought it was the fuel pump and by jarring it, by hitting it with a mallet would allow it to start and he was right. He also told me that if it happened again I could probably get away with that one or two more times but I would definitely have to have the fuel pump looked at. *Is there anybody here who could confirm something like this even being possibly true?
It didn't want to turn over a few days after the roadside guy gave it the fix, so I climbed under while my friend tried the ignition. Again, it started.
Today, after another 2 days of no problems starting. It dud t again. This time it wouldn't start. If it is the fuel pump, should I be expecting a hefty bill?
Thanks a lot and looking forward to your response. Happy Saab'bing!
Mathew