Use the following trick if you want to modify, repair, or create a weapon but are short on money. If the craft table is inside of a store, search the cash register. Occasionally you can find a couple hundred dollars.

Reach the City and have already discovered the Church and the Warehouse. Go to the Warehouse and obtain the hammer and baseball bat. Fast travel to the Church and sell them for about $400. Return to the Warehouse and repeat the process as many times as desired.