October 30, 2015 by: This post may contain affiliate linksMega Bloks First Builders Deluxe Building Bag Only $20.99 – Lowest Price! For a limited time you can this Mega Bloks First Builders Deluxe Building Bag for only $20.99 (reg. $29.99!) which is the lowest price we’ve seen on this item! Even better, shipping is free on $35+ orders get FREE 2-day shipping with Amazon Prime.