Every year, PNC Bank publishes its "12 Days of Christmas Index". The index compares current and historic costs of the goods and services described in the song. So, while I don't recommend giving your honey "eight maids a-milking" (unless you're into that sort of thing), my guess is that the "nine ladies dancing" cost is on the low side.
That is, unless Tony Soprano is running a holiday special at the Bada Bing.
