I started out with a Freedom trolly when round got bigger had a vanmount fitted from the same company.
I looked around at various systems, yes prices do differ, but what Freedom had to offer was a system what I could afford,
I also looked at what I could do myself on mantinance, how quick i could get parts, and what the after sales service was like,
I must say that I am very happy how I was looked after when I first started out, I did things wrong because it was new to me they were always helpfull,
I also hear they now give free traing with a City and Guild WFP Window Cleaner with any tank fitted by them
My advice is take your time look at al the things you want get prices, visit the companys, look what they have to offer, when it comes down to buying your system £6000 or £850 its 000 TDS that has to clean windows