trying to figure out when to replace fuel pump or should i try something else

What is your question?

van running great but suddenly start running rough and will die. try starting again and starts but then dies again,let van sit for a few mins then try and will start, though it was the fuel filter than needed to be replace, but yesterday van start stalling again and died on me,just wudn't start,change fuel filter and nothing,after trying a few times had to have it towed to my house, change sparks plugs and wires and start perfectly fine. This morning even put some B-12 to make sure injectors get real clean, was driving it n start doing same thing n died on me again, try starting and will start and died right away or sometimes started and run for bout 5 secs and died again, left van sit for bout 3 hours wen back and start right away without any problem, question is: Should i replace fuel pump or anything else i should do before spending $350 in replacing a fuel pump, thanks for your time