As you might expect, one of the easiest ways to check the value of a card is to look it up on an auction site like eBay
The Impact of Foils and Special Treatments on Card Counts The introduction of foil cards in 1999 with the Urzas Legacy expansion dramatically expanded the definition of a unique card
It even scales better than the Battle Priest, since it can start outlasting a turn earlier, and the extra point of toughness gives it more of a cushion against damage
For over a year control decks got to be at or near the top of Standard, and without Mirari's Wake it is doubtful they would have seen much play at all
If nothing else, a quick Google search will help when evaluating a card you can simply compare pictures
Its a whole other level of the game, Ive learned, just making these minor adjustments, working out ifsayhaving a Lady card in your deck, that lets you pull four Energies from the deck in one turn, is more efficient than loading up with so much Energy that you can rely on the odds of their landing in your hand