ConnecTiles – Magnetic Tile Building Kit Clear Colors 100 Piece Set – Link 
This is currently at it’s lowest price to date on Amazon, at just $69.95 w/free shipping!
This is a highly rated set with a 4.6 star rating.
- 100-piece set of multi-colored, geometric magnetic building tiles with project guide
- Square and triangular tiles adhere on all sides for infinite 2D and 3D building possibilities
- Open-ended manipulative building set engages children of all ages in creative play
- Develops spatial awareness and problem-solving, logical thinking, and math reasoning
- Recommended for children from 3 and up; hours of fun for children and adults