1995 Cavalier Fuel Pump

1995 Z-24 Cavalier ( 71,000 miles ) intermitant starting problem - once every 3-4 weeks, spray Gum-Solve in and starts right up. Leads to thinking the fuel pump is the problem, but at $443.00 for the pump plus labor, need to know what else could be the problem? Is there an aftermarket external pump that will work? Thanks for your help.
Twomotor

the fuel pump is not the problem. If your fuel pump was bad, your car wouldn't stay running. Your injectors could be bad or you could have a clogged filter.