Tasha's Hideous Laughter requires "tiny tarts and a feather that is waved in the air," Color Spray requires "a pinch of powder or sand that is colored red, yellow, and blue" and Minor Illusion requires "a bit of fleece". I don't mind having to spend some GP every once in a while to re-stock, but I haven't realistically had a chance to do so during the course of this adventure. I guess we could say that he already had a few tarts in his rations, picked up some feathers and fleece in the woods, and... had some colored powder in his thieves' tools?
I am certainly not opposed to the "benign neglect" method of dealing with it, however.