i know the purefreedom van setup is well thought of, BUT you need to pay for that "installer / technician " his 125 quid a day, you need to pay andrew ( isnt that the owners name ) his profit, the unit they use costs , it all add's up
price the DIY option and the pro installed system, the DIY option is going to be cheaper everyday of the week, UNLESS they are buying in suck quantity of part the they are getting them very very cheap ( which inturn means they will sell the parts cheaper anyway )