Answer:
It depends on the market size, time slot, and popularity of the host. The salary range is very diverse. Some hosts make just above hourly minimum wage while others bring in millions. Typically, if you are in a city with a small population (300,000 or less) you can look to make 30k a year. If you are in a city larger than that you can stand to make 50k-70k. The reason salaries are so much lower than expected is because the competition is high. There are a lot of people who are just dying to get behind the mic and will do it for peanuts. However, great hosts are hard to find and can demand a much larger paycheck.
Howard Stern is the most popular example of a host raking in the dough. He is paid a cool $100 MILLION a YEAR while most hosts in the morning drive are eager to crack six figures..