I am totally in love with these!! I picked them up at Wal-Mart for 1.98 a pack(4 in a pack). I had to go to two stores to get enough for my larger classes(27 students). They work well...clean up easy...and are pretty sturdy!! My Ks have not been putting enough force behind it...but I don't think that will be an issue for the older students. I don't know if this line of products is being phased out...or they just haven't restocked since Christmas in the craft section?! I wouldn't wait though if you are interested in getting them.
Yes..you could make them...or collect found objects...but with 3 kids..."Nobody got time for that!"