UNI-T UT136B Multimeters ($16.56 each)
JDS2023 Handheld oscilloscope ($113 + battery)
Eagle CAD Schematic/Layout ($0)
Ferrule Crimper Ferrule Crimper, to eliminate problems caused by stray wire strands ($23.99)
20 AWG Ferrules 20 AWG Ferrules, as above. $3.99/20 pcs
18 AWG Ferrules 18 AWG Ferrules, as above, $3.99/20 pcs
PWM Crimper Crimper for building PWM cables, Micro-Fit Encoder cables, etc ($39.95)
Desoldering Tool Weller desoldering tool. $25.60 ($6 shipped from amazon and $2-5 from banggood)
12V/7AH batteries for Peanut Bots $14.90 Cheapest price I've found (amazon has 'em too)