Optimizing broadcast media requires skilled execution.
The most effective broadcast media is TV and it may be very affordable through your local cable system. Visual impact is powerful.
Radio has lost a great deal of its impact due to other music, news & sports options... but it still works when properly applied.
The idea behind either medium (TV or radio) is clearly distinguishing your business from all others. If you limit your message to audio (radio), its wise to develop a consistent format supported by a short music jingle, catch phrase or mascot (character association).
Since radio coverage is fleeting, it's best to consider a saturation campaign to assure consistent coverage. Your effort must have impact along with a "call to action" that motivates a response. Some advertisers use a special promotion with great success.
Time frame coverage is typically a 2-week campaign, with a "Plan B" series if the initial thrust fizzles... or is a loser right out of the gate. Drive time news positioning is ideal.
I suggest developing a comprehensive program that uses broadcast and print, along with on-site reinforcement of whatever promotion you choose to develop. Integrate all media with the same message that is simply presented utilizing the strength of each particular medium.
Seeking out some professional assistance makes good sense.
When it comes to advertising, there is always room for negotiation. ALWAYS. And don't overlook the resource of using barter power. I love to wheel & deal with barter relationships... because your money goes much further... and you've captured a new audience... and developed new network relationships. Anyone ignoring the power of barter is missing a great resource!
-Steve