There isn't an easy to do this, but if you really, really want to do this, you could try to write a shitty android app and buy it yourself. You'd lose some money to Google, and its a lot more trouble than its worth, but if you really want to convert it to cash, that method works.

Edit: After some research, I found this:

Transaction fees

For applications and in-app products that you sell on Google Play, the transaction fee is equivalent to 30% of the price.

You receive 70% of the payment. The remaining 30% goes to the distribution partner and operating fees.

Source: https://support.google.com/googleplay/android-developer/answer/112622?hl=en