To summarize what just happened (in record time I might add), if you are a DIY'er with a soldering iron, you can make your own MTH tach boards for less than $1 each. And that includes shipping!
The QRE1113 sensor chip is WIDELY available. In addition to the aliexpress (Asia) site I showed earlier where the chip is ~25 cents a piece, it is available from essentially everywhere - eBay, Amazon, and of course DigiKey and other mainstream parts distributors.