Warhammer commander decks have exploded over the past year. They've been out of print for almost 3 years now and we can see the effects.
Dr. Who was released a year after Warhammer 40k. If we believe the trend will continue with Universes Beyond, Dr. Who could be a great buy. The commander decks for Dr. Who are currently around $180 per set, with the collector boxes around $335. If I remember correctly, they were around this price at release. This is a great opportunity to buy.