This story is the third in a series on television ad buys on local stations. Earlier: Young Guns set sights on Tierney-Tisei race and Kennedy places orders for $450,000 in TV ads.

A 30-second Massachusetts political ad running on ABC’s Modern Family in October is expected to cost $30,000, while the same spot will cost $15,000 on Dancing with the Stars and $1,400 on Chronicle.

Those are some of the prices that can be gleaned from the political advertising filings of local TV stations  on the website of the Federal Communications Commission. The website not only shows what ad time politicians are buying but what the stations are charging for that time.

WCVB-TV (Channel 5), the local ABC affiliate, tends to receive the most money for its ads because its ratings are high and it offers good access to the coveted political demographic of 35- to 54-year-olds. Since Aug. 2, Channel 5 has raked in $1.3 million in ad payments or orders, followed by WBZ-TV (Channel 4) at $916,682, WHDH-TV (Channel 7) at $600,100, and WFXT-TV (Channel 25) at $552,500. Typically, 15 percent of a politician’s ad payment is remitted to the ad agency placing the ad.

The filings indicate most political ads tend to congregate around local news shows that appear throughout the day. Charges vary, with prices as low as $25 for a 30-second spot on a predawn news show in August on Channel 25 all the way up to $1,800 for a spot on the Channel  5 news at 11. Channel 7 charges $1,500 for a 30-second spot on its late news, while Channel  4 charges $1,620. Channel 25 charges $1,000 for its 10 p.m. news show.

The pricing shows who is the king of late-night comedy. The filings indicate Channel  7 receives $1,200 for a 30-second spot on the Tonight Show with Jay Leno, Channel  4 gets $350 for the same-length spot on the Late Show with David Letterman, and Channel  5 charges  $105 to $200 for a spot on the Jimmy Kimmel show. Saturday Night Live charges as much as $2,500 for a 30-second spot.

Here are some other charges for 30-second spots that pop up in the FCC filings: Good Morning America ($1,000), Regis & Kelly ($600), Ellen ($500), The View ($700), Eagles and Patriots preseason game  ($7,000), CSI Crime Scene Investigation ($5,000), Dr. Oz ($50 to $150), Dr. Phil ($190), and ($75).

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