costs for gutter system
reliable transit and water tank......which you have. upto £15,000
vac and 30 foot pole...upto £1200
generator upto £800
pressure washer upto £1000
pole for spike upto £500 *can also be used for powerwashing down pipes
pole for camera £250
camera system upto £850
Its quite feasible to spend upto £20k on a system with van and tank,most will come in cheaper than this,yr nxt problem will be getting the customers.
..Also make sure your water tank is securely fixed to the floor/chassis