I would try Book-Off on 45th Street, just east of 5th Avenue. I just bought the OBCR of Rent for 8 dollars from there. They also buy back unwanted cds and dvds.
Other than that, try Barnes & Noble or Best Buy on 5th ave. Unless you want to spend a ridiculous amount of money and get them at the shop next to the St. James.
I used to spend hours in Virgin going from listening station to listening station every Tuesday when I was in school. Hours. Tower was even better with the scan music stations that sometimes gave you the full album instead of previews.
Then I switched to going to Colony and browsing sheet music for my pre-show entertainment needs when I moved out of the city.
Now I just hope my train isn't delayed and I make it in time for the curtain when I go to see a show.
What I miss the most is the Barnes and Noble that was across from Lincoln Center. Spent countless evenings after dinner there before a show or opera at the Met, Vivian Beaumont, Mitzi E. Newhouse, etc. And sometimes as an added treat if an artist had a new CD release they would actually perform selections live to a limited audience in a special room upstairs. And then there was a Tower Records store a block or so away to boot. I sure do miss those stores. They added a nice touch to attending events at Lincoln Center.