Here is the gears set that we have. The whole bucket is only $37.23 and is enough for 4 kids to play with happily. They really make some interesting things. I'm really surprised by how creative they can get.
The idea for the magnets came from our STEM teacher. I thought the kids would think they were boring but boy was I wrong. It is by far their most favorite center. It takes two of this set for 4 children. Each set is only $19.64.
I can't rave enough about these two educational toys. If you are looking to add in some activities that your child will really love and keep them occupied for a very long time then these are perfect.