"Nothing wrong at all with cash - up to the person receiving it whether they declare it or not - they are the evader if they don't".
Exactly!
I'm all for any payment method that allows anyone, but particularly a small business, to operate without paying the extortionate fees levied at them by the banks.
I wouldn't be arrogant enough to assume that payment in cash = payee avoids paying tax.
Some of our best local businesses are generations old, accept cash only, and are very reputable.
I imagine their tax contributions are proportionately higher than those of Tory boys with flash, expensive accountants.