Use self nocks instead of the plastic store bought ones. Save old bowstrings, and cut the loops off for string keepers, and use the string that's left to tie on nocking points. Same with old gloves. Cut the fingertips out and use them for string keepers. Make your own points from empty .38 casings, make quivers, sheaths, bow grips, etc. from Goodwill leather jackets, have your bird hunting buddies save their feathers for you.
As Poekoelan suggested, buy dowels from American Woodcrafters for about $25/100, or gather your own cane or shoots in the woods.
BTW, the bow itself doesn't have to be expensive. Some of the old garage sale Bears, Pearsons, etc. can be had for peanuts, and shoot as well as a new custom sometimes.
The list goes on and on.
Cheap is limited only by your imagination.