Since taxi fares are going to increase (and even the TLC commissioner admits that taxi ridership will probably drop), you could splurge on an extra special limited edition Metrocard holder from Hermes that goes for $150. While $150 is a lot of money if you're not Martha or an avid subway memorabilia collector, given that many people buy $70 monthly cards, even going as far as to get insurance for the card, $150 might not that much for a little piece of Hermes. It's like how everyone and her sorority sister got the Louis Vuitton accessories pouch, which at $230 is a little bit of Louis for the plebes.
Hermes is celebrating the subway's centennial with the card holder as well as a gorgeous exhibit of photographer Bruce Davidson's works at their boutique.
For the record, Gothamist uses a now-cracked plastic Metrocard holder we got for free from when the MoMA Queens opened (it helpfully tells us how to get to there). We tried the Scotte Vest but it didn't quite work out.