If you are like me you like to use a nice crispy (.WAV audio file) when you sample and not some slurpy ass mp3 file from iTunes, amazon, or a random torrent. Also paying for a sample that you are not sure is even going to work for a track can get costly as well. What I have done for years now is head to my local library and check out the selection. They have all kinds of CDs there in most cases (All Genres). You can borrow normally around 20 discs at a time totally free. Unless you bring them back late or damaged of course.
Take them home and rip all the tracks you want through you windows media player or straight into your DAW (or any other method that renders WAV files). Make sure if you are using windows media player you have the rip setting set to WAV (Lossless). Now you can create a large library of tracks you want to sample without spending a dime.
The other great thing that comes out of getting samples this way is you will try some samples out you never would have thought of. They have some really crazy stuff in there usually.