I did not choose a trolley system on cost, I chose and designed it to suit my own round.
I do Conwy marina, there is no access for a van on the seaward side, I would have to have at least 200 meters of hose to use with a van mount.
The greatest part of my round is highly compact, on some jobs I don't to move the van all day.
Parking is another issue, modern estates utilise every square inch of space, you have a job to find a place to park without being in someones way.
where there are major parking problems, you can drop a couple of containers off at strategic points.
Does changing two containers take up more time than winding in a hose and moving the van?
I really doubt it.
The only difference between my system and a van mount is the amount of water at my disposal at any given time, I can put in an eight hour day and use less than ten containers, and that's on compact work, no driving time involved, the Varistream on number 2 setting is adequate for me, Jeff Brimble uses even less.
It takes 90 seconds to set up the system, for the odd stand alone job that I do, I use a backpack on a small trolley.
If I had a lot of stand alone jobs or large office blocks, I would invest in a van mount, but for my round I wouldn't change one for my system, it's horses for courses.
I spent £600 to get into WFP, that was with poles and everything, with TDS in the 50's I don't use an RO, using the two vessels in line system I keep my water costs under £1 a day.
I could have bought a ready made trolley system, but I needed one I could stand on to unlock gates, and one that could carry 50 litres and never get rusty.