I've just added the functionality for ordering A4 reproductions of my paintings to my website. I take scans of each picture so every painting is available, apart from Eventide 3800 which was sold in the days before I took scans. It was talking to another artist Jean Briers that convinced me that it would be worth it, as A4 prints are the most popular size. They are easy to frame and post.
I've got a Canon Pixma printer with archival ChromaLife100 inks and some Somerset rag paper for giclee prints, so the hard part was setting up the website so that each page had a unique PayPal button. I used a php script to send the name of the painting to the PayPal form, so prices and the general layout of the order buttons can be changed for all paintings easily.
