ahh yess i see i see. i'm not too familiar with the technicalities of mp3 encoding myself but in my experience the CD is always larger before burning
Before burning:

After burning:

Notice the difference in da Megamans. so it sounds a tad noobish but what I do is rip from itunes. iTunes should have the CD under "Devices" and then you press import CD in the bottom right corner. my hypotaseees is that iTunes compresses the MP3 after the rip. (so you may notice a bit of a drop in quality) shit on CDs you get from best buy or yo daddy's drawer isnt meant to be ripped for iPods but be extra good quality for your car radio while driving with the convertible top down. so that may be why it's like 50 mb.