I have found that the best crafts that are cheap are found on meetup. You can put in your home city and crafts and you'll be able to find places near by that make crafts for cheap - or even free, and you'll get to know your community better.
Another place to get crafts for kids for cheap is your community parks. If you search online you should be able to find different groups that get together and make things. I live in a bigger city and I was suprised to find that small communities very near my house make things all the time. I think I have spent a total of $20 for a year.