I mine item prices for ItemPrice-1.1 from the armory. I mainly do this from the US armory because the EU armory seems to be working really poor. I often can't connect at all and sometimes I get "null data" returned. I know there are others who mine from the armory and I would love to hear if you have similar issues.
It's not a huge problem for my purpose. The EU and US item databases do have different items listed - but only very few. It still annoys me, though. I even live in EU, so my connection ought to be better. :P