Would this have affected the fuel consumption its been very poor recently

Got the final bill, £613, new Cam, shells, 8 lifters, new fuel pump and rocker cover gaskets, oil and filter :'( :'(

He showed me the old cam one of the lobes was totally warn away and the lifters where warn right through.

Result though its the quietest its ever been and feels like it has a lot more power, just got to take it easy and let it bed in for the first 1000 miles