i started out on this expensive hobby with IEM's as well, the e3c's. back then the e4c wasn't out yet... but i can say that IEM's will be an enjoyable experience for you, especially if you're always on the go. it blocks out external noise extremely well (with a good seal), leaving only you and your music. i find it very beneficial if you study alot outside - starbucks - like i do. i can sit next to the damn coffee grinders and blenders without hearing anything.
as far as the audio quality, since you have cds, trying ripping them in different quality - 128, 192, 320, lossless, and see for yourself if you can tell the difference. it only matters if YOU can tell that difference, regardless if someone says so and so quality is the best. i can hardly tell the difference between 320 and lossless and therefore i have most of my cds ripped at 320. lossless waste more battery and takes longer to load on my ipod. hope this helps...