I just a samsung t619 from t-mobile, and i downloaded a ringtone, it cost me $3 and its the worst part of the song and the quality is low, is there any way that i can transfer songs or midis from my computer to my phone, or get cheap or free ringtones? if so how or where?

Free Ringtones, Wallpapers, Videos, Games - FunForMobile has some for free.

If you can send ringtones to your phone check a few of my post for the name a nifty little tool I use.