Mike, in my opinion, the best place to download music is Amazon.com.The reason for this is that the songs are only 99 cents and they can be played on ANY device that supports MP3, which most do today. This is not the case for iTunes.
eMusic seems to be up and coming...you get a bunch of free music when you sign up and you pay by the month for a plan of your choice. I didn't take the cheapest, but the cost equals half of any other site per down load.I almost backed out of it because they offer a lot, but don't have everything available...but in the past few months that has changed for the better.The real down side is, if you don't use your subscription for the month...those credits don't roll over and you lose them...
If you don't mind funding our European Cousins, www.legalsounds.com. Usually about $0.09 a song and in standard MP3 format. It may take a bit for a new album to come out, but if it's even semi-popular, it will make it there. Downside, the quality is sometimes dicey on newer releases. You have to frontload your account, but the more you load, the more free downloads you get.
Nothing under 164.