All of these cards can be cast for their front side casting cost, or the alternate More Than Meets The Eye cost, to have it enter the battlefield converted on its back side, similar to transforming effects found on many werewolf cards
I really like Hunters Insight out of the bunch
These cards range in value, with the cheapest being $500 and the most expensive being $2400
Brago, King Eternal is the premier blink commander, blinking all your nonland permanents on combat damage
Or do what an increasing number of people do, and build an MTG Commander deck - it's a lot less painful to buy that mythic rare when you only need one copy.
If Your Deck Is Built Around Milling In a dedicated mill deck, milling is, of course, appropriate