Bids are based on the target. $50 CPM is extremely high for most niches, though. If you could talk about the vertical industry you are focusing, then it would be more approachable. Generally on CPA networks, most people divide into markets to benchmarks their results, not a general rule thumb.
With less than 10% CTR it's possible to go under $5 CPM for certain niches and certain countries, meaning less than 5c/click. Even the country is relevant in the equation.