Walmart offers the Learning Resources Robot Mouse STEM Activity Set, model no. LER2831, for $31.49. (Amazon offers it for the same price with free shipping for Prime members.) Opt for in-store pickup to avoid the $5.97 shipping charge. That's the lowest price we could find by $27. It includes 30 double-sided coding cards, 10 double-sided activity cards, 16 maze grids, 22 maze walls, three tunnels, a cheese wedge, a light-up mouse, and an activity guide.