My van was only £4000 when i bought it 7 years ago on finance. Its been paid now 2 years so it doesn't cost anything in finance now.
Van Tank, static tank, pole, di, merlin ro, pump, hose reel and hoses and gubbins all in for £800 from fleabay.
Last year i turned over £45,300 and only 3 and a 3rd days a week at that.
This year we hope to hit 60k a year, and im buying a cheap van and tank as above for 3k if i can and get someone in it and keep pushing forward. I am already approaching £51,000.
You don't need to spend 30k on vans and equipment to have a profitable business. Its all snake oil, customers dont care if you have ionics systems with go faster stripes. They just want thier windows cleaned to a high standard with minimum fuss. Make that your goal and you will always have plenty of work.