The best way to start is to either hit the lottery or hope a very rich relative remembers you in their will.

ASCAP and BMI rates are just a drop in the bucket and the least of your concerns.

Joking aside, it is a very expensive proposition, but like anything location determines the price.   Most of the radio frequencies have been assigned by the FCC and it is doubtful to find a new frequency in an urban area. You might have some luck in rural areas, but you will need to hire lawyers and do a number of searches and reports. IF you find a frequency you will need to spend a lot of time preparing reports to the FCC - and if someone else is trying for the signal you will have to make a strong case on how you can serve the public.

You might find a station that has a license up for renewal, and if you can make a strong case as to why the station is not serving the public you just might be awarded the frequency - but you will have to prove you can do a better job. This route is extremely difficult and rarely works.

The best bet is to find that rich relative who isn't looking very good and play up how you were always their favorite niece or nephew.   You might find a station that is up for sale, but the price even for a small rural station will probably run in the high six or low seven figures - and no, I'm not counting decimal points.   There are a number of outlets where you can find stations that are up for sale, notably Broadcasting and Cable magazine.

My station, WFDU-FM (Fairleigh Dickinson University) shares the frequency with WNYU (New York University).   The frequency (89.1) was assigned to the United Nations in New York as part of their charter. In the early 70's, the UN decided that it wasn't using the frequency and both universities applied. The FCC using the wisdom of Solomon decided to split the frequency between us. It has actually worked quite well.

In recent years the FCC has been tinkering with low powered AM stations. There are AM frequencies that can be operated at low power (just a few miles) and the FCC has been planning to grant licenses to organizations that can use these frequencies to serve their community. I can imagine townships, schools and non-profit groups using them to provide community service.

Wilco, I do wish you luck.   Anything can happen and it is not impossible. Let me know when I can send you my resume!   I would love to have my show air on more than one station!

Ron