After a lot of looking around to find the best way of doing this I have decided to start selling prints through the new Hub service at The Print Space. The Print Space offers an excellent print service for photographers, both online and at their base in London. The Hub makes it possible to offer print sales through links on social media and websites like this one. It allows photographers to control, or at least limit the range of paper, print type, and sizing, which is useful when preparing images for sale. For digital, one-offs, signed copies and editions it is still best to get in touch using the contact form, but this should make general sales much easier.
I've had more interest in the picture above than probably any other on this site, so I made the Reflections on Liverpool series, of which it is a part, available first. This is an ongoing project, but the initial set of eight images is here: Reflections on Liverpool.