Makershed
http://www.makershed.com
Barnes and Noble
http://www.barnesandnoble.com/b/hobbies-collectibles/hobbies/tech-electronics/_/N-1glsZ1qmi
Adafruit
http://www.adafruit.com
Amazon.com
http://www.amazon.com/STEM-Toys-Store/b?ie=UTF8&node=11021999011
Amazon.com STEM Club Toy Subscription
https://www.amazon.com/STEM-Club-Toy-Subscription-year/dp/B01M71IUZ7
Bitbox Coding for Kids Subscriptions
https://bitsbox.com/