Wiktionary
n. (context idiomatic English) A considerable amount of money; a high price or a high income.
Wikipedia
"Pretty Penny" is a 1995 promo single from Stone Temple Pilots' 1994 album Purple. It differs greatly in style from the rest of the songs on the album, and serves as a calm, old-fashioned interlude between the distorted and delirious "Still Remains" and the aggressive, sinister "Silvergun Superman".
According to lead vocalist Scott Weiland, this song was his last desperate attempt to prove to himself that he was not a drug addict; his heroin addiction later became a huge problem for the band and led to two hiatuses.
Scott Weiland stated the following in a RIP magazine interview in 1994:
In 2013 without Weiland, the song was performed again by the three remaining members of the band with their new lead vocalist Chester Bennington of Linkin Park and Dead by Sunrise. The song can be heard on KROQ, and a video of their performance at a different location to where it's played can be seen on YouTube, which was uploaded by its user.
Usage examples of "pretty penny".
There be a fine piece of bog oak close by that will bring a pretty penny, but I'll need a strong hand or two.
We ended up with a hundred and twenty-five, who would promise to give us all their faeces, properly contained in the special receptacles we provided (and they cost a pretty penny, let me tell you), as fresh as possible, and over considerable lengths of time, because you want serial inspection if you are going to get anywhere.
And then I'll tell her what the plot of Arthur of Britain is to be and you and Pretty Penny must start feeding her words as fast as you can go.
Ayeeyah, it is going to cost Lincoln Bartlett a pretty penny for daring to stick this.