If you haven’t been watching the MTG Stocks Interests page this week, you may have missed the movement on Astral Dragon, especially the Extended Art variant. I picked up 12 copies a couple weeks ago for $3.50/average price without thinking it would start moving this quickly. There are still copies available through SCG and overseas for $4.50-5.50 range, but Direct is already at $7 and trending up quickly. If you need a copy for play now is as good a time as any to grab one. The regular commander precon variant is trending toward $4 as well.
It might be too late already to get this for spec purposes unless you find stragglers that haven’t been repriced, but I wanted to advise the train is officially leaving the station.