First create an account on the hexbug website. They will send you an email coupon WELCOME that is 15% off an order. The coupon only activates after creating an account.
Hexbug.com has their Hexmas deals going on.. one of the best ones is the Stem Zone Bundle. The bundle includes two of the construction zone sets and one build blitz set.
The total bundle costs $139.99 and if you apply the 15% off coupon, comes down to $118.99 before taxes. Shipping is free. [hexbug.com]
Just to give you an idea of the value - The cost of each construction zone set is $69.99 as seen in Amazon.com link below and each build blitz set is $149.99.
The best part is that you have an extra gift that you can use later.
They have other deals too at the following
I hope it helps and enjoy