Ummm - no. Itunes default now is aac256, so unless the OP has intentionally downloaded as aac128 - then the file quality should be OK Also aac is generally regarded as being a better container for lossy files - with aac256 accepted as being at least equal to mp3 320 if not better. Personally I find them indistinguishable. Any other difference would be in the actual mastering. If you want to try (the software is all free) - have a look at this thread (
http://www.head-fi.org/t/655879/setting-up-an-abx-test-simple-guide-to-ripping-tagging-transcoding).
Take any CD - rip to lossless - then transcode the lossless to two copies - one aac256 and the other mp3 320. Highly doubtful you can successfully and consistently abx (ie blind) the aac256 from the mp3 320 - let alone from the actual lossless file.
Agree on the price - you can buy CDs cheaper - then just rip them yourself. As far as SQ goes - nope. Mastering may be different, and that's what you have to watch.
Nope again. At least with iTunes you know what you're
buying. Torrenting is illegal and there would be no guarantee that the file quality would be any better.
There is no difference between WAV and FLAC - apart from file size (FLAC is compressed - but still lossless). Both will send the same PCM signal. It doesn't matter how good your system is - as long as their are no errors in decoding, and both are from the same master digital file, both volume matched and tested under a proper blind abx - no-one will be able to tell them apart.