Order Zumba online on the Internet from the official Zumba Network. If you shop elsewhere you need to be extra careful with the quality of the material. Therefore, I suggest that you check your sources first and foremost and thus avoid unpleasant surprises. The Zumba online is the best place to shop, but even here you have to look into their terms and conditions. Find out about the shipping details, the shipment cost and the possible discount, if there is any available.
A copied Zumba online that does not respect the copyright law will not provide the quality you need, not to mention that it is illegal. Therefore, we once again stress out the fact that you check your sources well, and not be fooled into bad deals because of your eagerness to save a few bucks. Zumba has lots of fans and you can easily become one of them. Make sure you do get what's best. One other advantage you have with a 'home' trainer is that you can pause it whenever you feel that you can no longer practice, and thus you can follow your own rhythm.