As someone who really enjoys the immersion of a game I want to recommend this Kickstarter as being high on sound quality and extremely affordable.
He rebooted this kickstarter tonight after lowering the price, shortening the time until fulfillment and even adding separate categories for those who may like ambient (background) music and sound but not the SFX (weapons, traps, monsters, etc.) with more a la carte levels.
Here's the track list so far (upper levels allow backers to collaborate with Wes, ie. I'm in for $100 Monster level to create (10) Pathfinder-TYPE Goblin tracks for Monster sounds - available to all Comlpete Reward levels as well!):
https://docs.google.com/spreadsheet/ccc?key=0ArAfdauqchy9dDhCTHl3Y2tIejc2Qk ZkaGNzT1BMZVE&usp=sharing#gid=0
Here's the link for those interested in adding sounds to their live OR online gaming:
http://www.kickstarter.com/projects/1281758745/pro-tabletop-gaming-audio-co llection
(NOTE: collection is one word in case you are seeing it split like me)
You can also just search for it on kickstarter by the name of this thread.
I was in on his first Kickstarter (as were over 1300 others) and was VERY happy with what I got. As a Complete Rewards backer for $50 is 266 MP3's (not factoring in stretch goals or upper backer levels) I believe. And Ambients and Music are 10 minutes each. That's less than $0.19/MP3. There are also $25 levels for those who only want Weapons & Spells, Monsters & Traps OR Sounds & Music.
Enjoy!