Some of the ringtones are low quality, you have to look a bit around for a high quality one. But when its free (which free is very budget friendly) you just have to figure out how to get what you want. I also think it depends on your phone about the ringtone quality you need. if your phone is a standard cell with one lil mid grade speaker you wont hear a difference, but if you have a nice phone with lil stereo speakers, or has "mp3 player" worthy speakers you will clearly hear the difference. I can tell you that zedge.net usually has some good ringtones on it. and usually if you do a search for a song, lets say "poker face" there will be 10+ different results of it. ranging in sound quality and different parts of the song itself. The one thing i've learned is when you are trying to be "budget/economical/freebie" sometimes you just have to know how to play the system to get what you want.
With that said, when i cant find a ring-tone i want/need... i just make my own ringtone on my mac computer. there are a couple of audio editing programs i found for free that allows you to crop music, change the bit rate(sound quality) of a song i already own. Usually if its a disney/movie/misc sound that is NOT a song i can find a wav/mp3 clip online and convert it to meet the ringtone needs. I currently have over 600 ringtones and 700+ wallpapers on my cell phone (love those Micro SD cards). My partner calls me the "cellphone DJ" because if you say it... its on my phone.. haha.. disney, muppets, billie holiday, lada gaga, etc...
I love being budget savvy... (it allows me to splurge in other areas with my money)