The number of axles you need depends solely on the amount of cargo weight you intend to transport. Make sure to take the time to do your research. Most if not all the weight information you need can easily be found on the internet.
Important! If you cut corners to save money and not have the number of axles needed to haul your cargo weight, the structure of your trailer may fail. This could result in serious injury to you and others, and possibly destroy your trailer and other vehicles.
Having not enough axles for the weight of your cargo will also effect the way you trailer handles while towing it down the road. It will also cause excessive and uneven wear of your tire and cause damage to you wheel bearings and other parts of your trailer.
A tire could easily rupture, causing you to lose control of your vehicle and the trailer.
In the end, its best to configure your trailer to hold a more than your expected cargo weight. In addition, damage caused from overloading your trailer will not be covered by warranty.
Be sure and provide accurate information to your dealer so they will make sure you purchase a trailer with the right number of axles.