Yes, so in other words:
cost = 8
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text = "Whenever your
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creature dies, add a random
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card to your deck and regain one third of the card cost."
I'd use it. It will make
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pheonix decks pretty ugly. In order to be rid of your pheonix they will have to kill it twice, giving you back 2/3 of the cost and 2 random
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cards. This will make players think twice before killing off fire creatures, which are otherwise often quite fragile. With a soul catcher or two in place, you might even be able to thread this into an otherwise mono
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deck.
An even more potent alternative would be:
"Whenever your
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cards is destroyed, add a random
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card to your deck and regain one third of the card cost."
Then this works for destroyed
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permanents as well (creatures - ashes, permanents - dust... or maybe vice versa)