1994 Mazda 323 Battery is charged, but only a click when st

I am not thrilled with my garage as they seem to never know what is causing something, and charge me $95/hr to figure it out. My 323 was working fine, started every time.

There has been a problem with the exhaust smoking from the middle area of the car underneath. I figured I would need to replace the middle pipe. Today, I turned the key, there were dash lights and sounds, but just a click instead of any starting. I tried jump starting the battery to get a boost, but that didn't help.

Before I take the car to the garage, I need to have an idea what is wrong and how much it's going to cost. I have already put so much into it over the last three years. If it's the starter, can I bang on it like I used to on my Camaro to make it work? Is there anything else it could be? Thanks.