In July 2012, the bitcoin mining hash target required 14 leading hexadecimal zeros. Suppose at that time you joined a mining pool with your CPU that could mine 20 million hashes per second. What is the expected mining reward per month (30 days), as measured in dollars, if the block reward was 50 BTC and each BTC traded at about $7 USD per BTC?

Hint: first find the expected reward per second, then multiply by number of seconds in a month.

Enter answer in dollars, accurate to nearest penny.