Djuced is designed for . The cheapest option is the Hercules DJControl Mix (~$60 USD) or the Starlight (<$50). If you already own a Numark or Pioneer, Djuced may work in basic MIDI mode, but for full features, stick to Hercules.
Djuced offers a free version with limited features. You can download and use it without a license key. Keep in mind that the free version might have limitations compared to the full version. Djuced License Key Free
If you don't have a Hercules controller and want to explore other free options: Serato DJ Lite Djuced is designed for