audi 80 tdi fuel pump?

recently my audi cut out on me and wouldent start,i got told 2check the solonoid on the fuel pump.but still wudnt start,then got told i would need 2change the top half of the pump resulting inme spending nearly 400pounds,i dont have the funds and dont want 2lose the car,has any1 had this problem or even heard of it,please help.