I also own a Dingo and bought a dump trailer about 6 years ago and it was one of the best investments I made.
Reasons for a dump trailer:
1 Do not need insurance
2 Low maintenance ( tires only )
3 Can be left on a job for employees to use while I go to another job or to pick up additional materials
4 use as equipment trailer and a dump trailer
All and all it has been a huge money saver for me but sometimes a dump truck would be nice but not enough for me to purchase one I will keep my trailer for now.
7x14 PJ 14,000# paid just under $6000 new