I too have just been introduced to classical music as my new system sounds so good that I wanted to try more and different sounds than just my usual head banging faire. Been buying lots of stuff after getting advice here at the 'gone (See top 10 Classical CDs for Newbies dicussion)
Check out this site for good music cheap
http://www.arkivmusic.com/classical/main.jsp
Check out this site for good music cheap
http://www.arkivmusic.com/classical/main.jsp