Get the Parts
Please know that these are Amazon Affiliate links. This is how you can get these parts in bulk for the cheapest possible price. It cuts out the middle man (us). For some of these items (aluminium foil, markers, an individual set), a trip to your local dollar store would be the best/cheapest way to get supplies. For other items (paper clips, tea lights, binder clips), Amazon would be the best/cheapest option.
NOTE: Dollar store paper clips are often made from a silvery plastic and do not conduct electricity.
Tools
These tools are recommended. Most classrooms will have many of these, so there is no bundle link. A cardboard saw is a great and safer alternative to having kids cut cardboard.
Materials for One Learner
1 LED Tealight
11 small binder clips
2 paper clips
Aluminum foil
Cardboard
Small Group Complete Set
This will give you all of the tools and parts needed for a group under 12 people. The link for LED tealights is for 36, because it was cheaper (and better) than any similar product sold as 12. Remember to save your cardboard box to use to make the bricks.
Small Group Bundle Link
Materials:
12+ LED tealight (the link is for 36, because it is cheaper than 12)
Aluminum foil sheets (likely cheaper if found at the dollar store)
Full Class Complete Set
This will give you all of the supplies needed for a class of 18 to 36. Remember to save your cardboard box to make bricks. You will likely need more cardboard.
Full Class Bundle Link
Materials:
For over 21 kids, you will need two of these
Paper clips (Might be cheaper to buy locally. Make sure they are uncoated and metal)
Aluminum foil sheets (likely cheaper if found at the dollar store)
Other Bricks
Dollar Store Alarm (used for the Magic Wand Brick and Buzzer Brick)
Scrappy Clips
You will need 2 of these small paper clips to make a Scrappy Clip. This box of 100 will let you make 50 clips.