How do you guys normally check the value of your rare coins? For example, I was trying to check ebay for 2000 1 oz dragons and I'm not seeing any auctions ending any time soon. Are there other sites you guys check?
TBH I usually scan a basket of coin types (mainly krugerrands, but also eagles and sovereigns) on eBay - completed listings only (obviously) - and use that to work things out, estimating on the low side.
This used to be quite easy because volume was consistently high, with nearly all of them being the real thing. More recently there are fewer real coins on sale - with a sh*tload of them being plated clones or other trash (I don't mean fake sales, specifically, I just mean distracting crap that nobody in their right mind would want to touch). There has been a clear shift away from 'available quality' here.
I don't bother tracking premiums on the less common coins. I just assume they'll be similar and count them as krugerrands (i.e. anything + is a bonus).
OTOH I made sure all the less common coin types I chased were near spot so I wouldn't have to track them separately!
There are a couple of automated ebay-based coin premium tracking systems (one on Kitco and there is another on 24hgold.com IIRC) but I always thought those were subject to freak ebay listings - not enough filtering and averaging involved. Better done by eye perhaps, every few months? Your Mileage May Vary.
P.S. I've been kicking myself in the ass for not trading in my Krugs and Eagles back in 2000 when they were highly recommending the trade. It was going to cost me like $30 a coin or something and that seemed to high. Ugh.... Oh well, you can't win them all; I still have my Krugs and Eagles and they've done pretty well