If you are looking for some inexpensive gift ideas then canvas craft bags may be just the thing. There are many choices available to you. Some that already have their own design, or some that you can add your own design to by painting, stenciling, or stamping. There are so many ways to make it your own.
If you are in the market for making a gift to give then craft rings are also a good purchase to make. There are many things you can make with them and they come in a variety of sizes. I even saw a ring-making kit that I know, would be right up Allie's alley. Ba bum bump, lol, that is funny - Allie's Alley. Anyway, a gift any 6 year old would love.
My nephew would not enjoy a craft ring kit, but he might enjoy something made out of some captain america fabric. Now.. if only I could learn to sew. Actually, that link will take you to many options available for the little boy on your list - costumes, accessory kits, superhero clothes. I actually find my nephews the hardest people on my list to buy for. I have been a notoriously bad gift giver for all of my life. You would think I would get better as the years pass. I don't. My husband is not any better with his gift-giving skills. One year, he got me a hair toolbox. Yes, he did. But, that story is for another time.
Maybe I don't give myself enough credit. I do give my girls good presents,and they don't have to be expensive or one of the "hot" toys of the season either. Anything and everything is a good present to them. I wonder how long that will last?