This may be old news...
There's a website all about comic books called
Digital Webbing that also publishes a comic book called Digital Webbing Presents. Well, issue #24 has a TMNT variant cover. I'm not sure who did the cover. But there's also a TMNT story in the issue in color by Dan Berger and Andie Tong. You can see a thumbnail of the variant cover near the middle of the page at
http://www.digitalwebbing.com/comics/ordering/buydirect.html, and one of the pages from the story at
http://www.digitalwebbing.net/dwp/dwp24_preview.html. Getting the TMNT variant cover is pretty pricey too at $19.99, especially when compared to most other back issues are $3.99. Then again, the supply is supposed to be quite limited and it's a popular cover. I saw one eBay auction for the TMNT variant cover go for $51, so $20 ain't so bad.