no link, the place i bought mine from in august doesn't appear to have any anymore.
i recommend buying the esp-12e, and the first one on my search comes up at $1.97. note, these things aren't breadboard friendly out of the box. if you want that, buy a huzzah from adafruit or buy one of the breakout boards on aliexpress (17 cents each or so).
For the 12E to start with, take a look at the nodemcu dev boards. More expensive but it's a great little board to start a project on and then go to the bare module since it includes all the usb<->ttl, and regulator stuff.
