Buying Stuff From Eric
You can buy all sorts of stuff featuring Eric's work from E.S. Productions, including dozens of Black & White and Color prints (many of them featuring images not available on the 'net), videos, T-Shirts and buttons, plus more. You can find the catalog below (the images are very large GIFs, suitable for printing). For more information and details on how to order, go to the E.S. Productions web site.
Buying Stuff in the UK
If, like me, you don't live in America, then buying stuff direct from Eric could be more awkward and expensive, so you might want to buy through someone more local. In the UK, you could try United Publications, who publish the Sabrina Online books and thus have good links with Eric. I've ordered the Sabrina comics and some print portfolios from them and the guy I spoke to was friendly and helpful and the stuff was delivered OK.