So now within 10 mins of new art being available on the secondary market, the available art will also appear within the auction saboteur forum. So just check the last 100 posts every now and again if you want to keep an eye on the Latest offers.
http://www.auctionsaboteur.co.uk/forum/aucsab_last100.php
(or RSS the feed to your own feed reader yourself, if you want to be really clever)