Pc atx 24 pin breakout board
Cheap esc for bldc ( but those yellow extra cheap ones have a tendency to burn up on high duty cycle loads )
Cheap bldc too, I use one plus a 3d printed fan + shroud to cool nvidia tesla gpus and another two to vent in/out garage door windows in summer
So many sensors
E ink screens plus esp32 or other mcu / sbc
Small touchscreens plus sbc for diy smart stuff
Cheap aluminum extrusion and fixings ( ryobi scroll saw is a relatively quiet and controlled way to deal with smaller stuff like 2020)
Cheap bms and mppt solar bois
Cheap rgb led stuff, I’m partial to the water proof silicone stuff, easy to pair with an esp32
A lot of tat is similarly priced on Amazon and the likes. Always worth a double check before defaulting to ali
Rctestflight
Cranktown city
This old Tony
And a few more but those are my favorites.