I will be able to quote an accurate radio advertising cost once we have discovered the right radio station to reach your target market. As a rough estimate, the cost of radio ads for one week can range from $3,000 to $6,000 if you are advertising on a capital city radio station in Australia.he cost for radio advertising is normally done on a per-spot basis. You will be charged every time your ad runs. So, if you want your ad to run 5 times per day for 7 days you will have a total of 35 ads.