Interesting hack, the hardware looks pretty nice and compact too. I should note that there are hundreds of different types of “smartcards” out there, and this is just emulating the contactless ones (and a subset at that). Still if there is a kit for $25 in the future, I would go for it. There are commercial readers/clones out there, but I think the cheapest I have seen was $300.
http://hackaday.com/2013/12/28/chameleon-emulates-contactless-smart-cards/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+hackaday%2FLgoM+%28Hack+a+Day%29
https://github.com/skuep/ChameleonMini/wiki