I purchased a used Hercules MK4 on Amazon that came with an LE version of Virtual DJ and had no problems. I also purchased a used Kontrol X1 MKII on Amazon (no software to worry about) when I bought the full version of Traktor Pro 2 through NI. Contacted NI about registering the X1 as it was still registered to whomever turned it over to Amazon and they were unable to contact the previous owner by email so it is a piece of unregistered kit, BUT it works.
Possibilities are that DJJUICED may require you to buy a new licence, especially if you want support. However, my Hercules had the Virtual DJ registration code on a sticker underneath the controller, check yours.
