Hey there!
I'm a percussionist/pianist that enjoys having good quality sheet music! In order to allow other people to have them also, I upload them to IMSLP!
I believe publishers deserve a benefit from all their editions. In order to allow them to keep editing pieces, buy the scores if you can!!! (IMSLP started in 2006, and prices for a Beethoven's Symphony No. 9 Full Score by Breitkopf & Härtel nowadays, compared to their original 2005 prices, is double the original price!!!)