So. 71p to avoid collecting from a customer. That's 4.7%, or just under 1/20th.
Thus, if a typical £15 job takes 20 minutes, then if collecting takes more than one minute, you're better off moving on to the next house and doing another clean. In my experience, collecting takes people a damned sight more than a minute to do, so you're goint to be much better off if you use PayPal than not. I love customers who ask me to leave them a slip to pay online rather than fumbling about for two minutes finding change or writing a cheque.
Vin