Approximate volume of a bag of Paver base is 0.5 cubic feet.
Approximate volume of a 50 lbs bag of sand you can use for laying Pavers is 0.5 cubic feet.
A cubic yard = 27 cubic feet. You would need to purchase 54 bags of these items to get one cubic yard of material.
Best place to buy would be at a gravel pit where for the price of a couple of bags you pick up a whole cubic yard. Even if you had to have a dump truck deliver a cubic yard of sand or crushed rock you would be cheaper off than purchasing it by the bag at your no longer "favourite box store"!