I love Michaels. But I'm lucky, I have an adult daughter and my mom who are both willing to spend money for the punches for me in Michael's for Christmas and Birthdays. Plus if you like little punches just for fun, the dollar stores have quite a few. They are only tiny, maybe only 1/2 inch or so, but they are cute too.
They are a medium weight card stock for most and a bit of scrapbook paper for the multicoloured ones. They aren't flimsy, but they aren't really stiff either.