Thanks for the tips. What I want is to sell prints, not the image itself (digital) and I don’t expect to sell more than one or two, so probably a free service like Photocrowd – that I’d never heard of before – will work best. I’ll check out all the ideas!
Not free, but have a look at Photium if you want to create your own site for selling pics.
I set up a website through it for a couple of years, just as a bit of a self-project to be honest.
The bloke who runs it (Will, I think) is excellent at getting back to you with support queries.
Definitely worth fiddling about with the 30day trial.