Cheapest i seen by far.
Create your own quarry with the Mega Bloks Mega Quarry Duffle Set. Little ones can set up a track to help Thomas get around the site and build Harold a helipad to land on.
Size H45.72, W29.21, D8.45cm.
For ages 2 years and over.
Also found another, similar deal for Boys and for £19.99:http://www.argos.co.uk/static/Product/partNumber/9076846.htm
Think the only difference is the color of the Pieces and the Box. Not sure.