Lol if you can’t afford to buy and run a heater with an outlay of 5 grand I think you need to either get a job working for a window cleaner with decent work or do something else,let’s be honest what other outlay have you got apart from poles.
Go and look at what the other trades like plumbers and electricians have to buy just so they can do the job,and don’t say they earn far more than window cleaners because I know for a fact they don’t,or shouldn’t be if you’ve been at this a while I think there’s a lot of window cleaners that are happy with what they do and don’t look for anything more as far as quality of work goes do what you’ve always done get what you’ve always got type of thing 😉.