Depends how old the truck is, some older models truck parts can be gotten and replaced cheaply from a junk yard, or also new semi cheap from US Auto parts on line. If its not the F-150 ford 1996 slanted engine you will not have much issues.
It depends on how loyal you feel to the truck you own. Personally, I would replace the fuel pump. I've had my truck for a while and have grown rather comfortable with it's little oddities and it's good points. It also depends on the miles. If your pushing up there in the miles a new one would be better and use the old one for a trade. Good Luck.