There are a limited amount of copies of WILD CARD available in the rewards because in order to give them to you, I have to buy them myself from the publisher. This causes some headaches in terms of royalties and number crunching, so I have to keep those copies at a minimum.
As of this post, the FLYNN+ ($30) rewards have been scooped up and only 2 of the SATYR+ ($55) rewards remain. When those are gone, they are gone. It is unlikely (though not impossible) that I will add more copies of WILD CARD to the rewards after that.
However, there is nothing to stop you from pledging at whatever level you please and buying a copy of WILD CARD right now. It is available on iTunes, Kobo, B&N, and Amazon.(as for example: http://www.amazon.com/Wild-Card-Entangled-Edge-ebook/dp/B00G8BTSZS/). In fact, that would be awesome, because you could read Wild Card NOW!