if you are using vdj pro, you have two options, keep using the cracked version get the mixtrack and use the audio 2 which is a better soundcard than the mixtrack.
buy the mixtrack pro which will let you upgrade to vdj pro for $150 so you can get vdj 8, but you wont have the best soundcard out of the two. the bonus of upgrading to pro is you get all the effects that have just been released which are definately worth the price of the upgrade.
If you are just learning the second option seems better as you don’t need a better soundcard for a standard stereo system, if your playing larger clubs you will really want a pro better soundcard than the audio 2.
If I were you I’d check ebay for any bargins on the mixtrack pro, just make sure the serial hasn’t already been upgraded.