Having $50 in birthday money, an hour to kill, and a CD Warehouse close by is a recipe for going somewhat over budget:
Missy Higgins - On a Clear Night
Jason Mraz - Mr. A-Z
Crowded House - Together Alone
Rick Astley - Greatest Hits
The English Beat - What is Beat?
Barenaked Ladies - Disc One: All Their Greatest Hits (1991-2001)
Crowded House - Woodface
Gin Blossoms - New Miserable Experience
Barenaked Ladies - Born on a Pirate Ship
Fleetwood Mac - Rumours
(Notice how I buried the guilty pleasure CD in there?)
The cool thing about buying used CDs is that I don't feel bad about buying an entire CD for one or two songs. A few of these fit that description nicely. I absolutely love the song "Where I Stood" off the Missy Higgins album, and I love her voice, but have no idea what the rest of it sounds like. Same goes for the two Crowded House albums.
As for the rest, they are either albums where I love every other album I have by the artist, and therefore, trust the band enough to pick up one where I know few songs (Barenaked Ladies' Born on a Pirate Ship and Jason Mraz), or I figure I can't go wrong with the greatest hits, or I know most of the songs and have wanted to buy the CD for years (Gin Blossoms, English Beat, and Fleetwood Mac).
I also ended up with the third in our "movies not about Christmas that happen during Christmas and are therefore awesome Christmas movies" collection. The first one was Love Actually, and then About a Boy. Now we have Just Friends. Chris Klein's scene where he sticks his head through the curtains and says, "Would you two like to join us in a carol to celebrate the birth of our Lord?" is worth the entire $5.99 price.