Hi
Why not use the priceguide

it's what it's there for!!! And it's based on all the recent auctions - the price guide has only been up a few weeks so some of the older set do not have as many auctions to go on but it still gives you a good guide to the current situation - here's the Sirius info:
http://www.theyakshack.co.uk/tradingcards/index.php?page=viewcard&card=5And actually yes I do have one for sale, please PM me with an offer. I can scan it if you are interested too.
Cheers
Roz