to the tune of 

1. Set to the musical composition of.

2. Used to mean "approximately", or "in the general range of", but usually only when talking about large sums of money.

1. When I heard Weird Al Yankovich's lyrics to the tune of "Beat It", I decided that maybe MTV really was a worthless tool of Satan.

2. Right: So then I had to pay something to the tune of $5,000 for a new one.

Wrong: So then I had to pay something to the tune of $0.05 for a new one.

Notice that the order of magnitude of the cash amount affects the usage of the phrase.

to the tune of by Al December 2, 2003

to the tune of 

An Idiom: To the sum or extent of.

"We're looking at jail time, Franky. Either that or a fine to the tune of $50,000."

to the tune of by AA November 2, 2003

to the tune of 

"around about" - approximately, roughly, in the region of. often applies to a monetary amount.

i heard an offer to the tune of 5 million dollars for this place.

to the tune of by Smiff November 3, 2003

to the tune of 

sounds like

The abc song is to the tune of twinkle twinkle little star

to the tune of by Brittany November 3, 2003

to the tune of 

estimate, close appraisal, rounded figure.

We are asking for donations to the tune of $1,000.

to the tune of by Chad Deese November 3, 2003

to the tune of 

in the range of

that computer will set you back to the tune of three thousand dollars

to the tune of by Random832 November 1, 2003

to the tune of 

To perform a physical act upon someone of something in time to a music tune

He dance around him to the tune of "stuck in the middle of you" before slicing the guy's ear off

to the tune of by Jim November 1, 2003