In message , at 11:11:38 on Sun, 14 Jul
2019, tim... remarked:

Then there's a few phones which need a "5v" SIM, and don't work with
a 3v one. Those SIMs are getting harder to find (some say that it's
only Pound-shop Orange SIMs these days,

Thinks

why would someone pay even as much as a pound for a SIM?

Because that's what the shops charge, and stealing them is a crime.

I've paid as little as 1P for a SIM in Tesco, and both I and the
checkout assistant were surprised (the shelf was marked 99p)

But they've been trained to believe what the till tells them.

That came with some free data for the first month, so not merely a bit
of plastic needing topping up.

Sainsbury's Mobile used to have some offers (their project flopped and
they did desperate stuff to try to kick start it). One of which was to
give people who bought a phone there, a voucher for a £10 top-up. But
the till regarded a £10 SIM [with one month's credit pre-installed] as a
'phone', so they were effectively free.
--
Roland Perry