It's going to take a lot of marbles and they're going to cost a big penny. But the rest of the materials are pretty cheap and I'm liking this. I know it doesn't look like much right now, but when it's done, I'm confident you'll like it if you're my age and grew up around here where we used Seagram's bags for our marbles.
It's going to take me forever, too. But I like that. And of course, because I'm using a hot glue gun, I'm regularly burning myself. Yes, I suffer for my "art." (I'm kidding.)