There are currently 4 tarifs:

*Seller Basic - 42.50GBP per year
  includes 25 images. 

*Seller Premium - 67.50 per year
  includes 200 images. 

*Combined_Basic - 65GBP per year
  includes up to 25 images and a website with .co.uk domain name

*Combined_Premium - 95GBP per year
  includes up to 200 images, a website with .co.uk domain,
  detailed visitor statistics and paypal integration so you can 
take credit card payments for selling your work. 

A full comparision of features can be found here
http://www.theartistsweb.co.uk/prices/