4SurplusCity via eBay offers the LittleBits Electronics Korg DIY Synth Kit
, model no. 650-0124, for $109.99
with free shipping
. That's the lowest total price we could find by $33 and the best deal we've seen for this kit. (Most stores charge around $159.) It features a keyboard, micro sequencer, oscillator, and many other modules that hook together via magnets in various combinations to create music. A 35-page guide book is included.