They are different products, not different price points
A standard portable toilet is a chemical holding unit. It has no running water, no climate control and no plumbing. It exists to be adequate, and for many situations that is exactly right.
A mobile restroom is a small, finished room. Le Duo has two entirely separate private suites, each with a flushing porcelain toilet, a running-water sink, a mirror, recessed lighting and powered ventilation, and the interior is heated and cooled.
When the plastic unit is the right answer
Long construction placements, large public events with heavy throughput, and remote sites with no power or water access are all cases where a standard unit does the job at a fraction of the cost. We will tell you when that is what you need.
When it is not
If your guests are in wardrobe, if the event is photographed, if talent or clients are on site, or if the restroom will sit in view of the party, the difference stops being about comfort and starts being about whether the event reads the way you intended.