eBay

I bought this used a few months ago to get back into things, but I don't have enough time. My loss is your gain!

Includes:

Kontrol S3 Controller

White USB-A to USB-C cable (not pictured)

Scrappy handmade cardboard+duct tape carrying case (not pictured), doesn't look good but it gets the job done

Does not include:

Any licenses to NI software such as Traktor Pro 3

Power source (it will run off USB power alone, but lighting/amplification is limited)

Any other cables besides USB listed above

Native Instruments Product Page:

https://www.native-instruments.com/en/products/traktor/dj-controllers/traktor-kontrol-s3/