Sadly, a lot of these dor to door folk who "are down on their luck", or selling on behalf of a "charity" are con artists.
Now, we never buy from them. They are another branch of the "pressure wash your drive?" , "clear your gutters?", or "Youn have a loose tile" brigands.
The real charities are bad enough, asking for a tenner a month, so that they can pay their CEOs £100+K p.a
Only the Sally Army chief behaves reasonably, based on recent newspaper surveys. He draws only £18K, and a lot of his staff get only £12K. m You wonder how they manage to live!
Very often, the smaller, local charities make better use of donations. Presumably, they don't have the overheads of a big office in some expensive city, and don't pay their staff big city bankers rates.
Cynicism, tends to be a good protection under these circumstances. Sad, but necessary, it seems.
Howard