Assuming the workers are employed full-time, $25/h is about $4000/month. That's a pretty good salary for an average programmer in Portugal (Europe!), even before taxes.
Yeah, that was my first guess, that the creators aren't in the US, and $50/hr is a good rate for a lot of developers that live in areas with a lower cost of living, etc.
Apart from the withholding of income tax (which I was already counting), I think they only pay social security (23.75%).
Considering that many professional programmers with a college degree in Software Engineering make ~$1300/m (net), the remaining $2700 is plenty to cover all taxes and expenses for both parties.