" Having to make contact first via e-mail and then perhaps (I don't know for sure) sending a cheque
is just too much bother for some (myself included)."

The one and only time I did this was about 10 years ago
when I'd exhausted all leads to every known online shop
looking for a long deleted CD by one of my favourite older and retired 'folkies'.
[a CD that was otherwise only available from an amazon seller for a stupidly outrageous price]

Then by chance I discovered the artists unpublicised page on an educational website,
and a note that that one or two CDs still remained in personal stock for sale at normal original retail price.

The CD arrived covered in scratches and finger smudges.

Oh well, it was still playable..

But more importantly, when I phoned to check availability
I was very pleasantly surprised [and at first tongue tied] to realise I was speaking directly to the artist in person;
who was quite happy to chat for a good 10 minutes....