Matts2k87

So im about to diagnose a fuel pressure issue. I went to buy a gauge to tap into my spare fuel rail when i noticed that it was half the price to buy an aftermarket AFPR than it was to buy just a liquid filled gauge. I dont have a tunable ECU but i figured i may be able to bump the fuel pressure back upto stock if its lacking. Its probably a stupid question but what i really want to know is, are these ebay FPRs worth a try or will it just lead me into more problems?
Cheers guys