I'm a 1L and I think LEEWS is worth it. I know others (e.g. LEEWS enthusiasts) may not recommend this, but if you don't want to spend over $100, and if you don't have the time to listen to the CD's, I would recommend just purchasing the manual for several reasons.
1) The CD's + Manual cost over $100.
2) The manual costs $35.
3) In my opinion, the manual has nearly everything that the CD's have, and it's more concise/to the point. In fact, I think the CD's left out some important information that the manual has.
4) If you're listening to the CD's, it's a pain in the ass to keep rewinding the parts that you don't quite understand.
5) He says not to take notes while listening to the CD's, and that it should take about two or three days to listen to them. (Although there is only 8 hours of actual audio, there are a lot of practice exercises that take a long time.) However, I couldn't help but take notes -- I felt that if I didn't, I wouldn't really absorb any of the information he was saying. I ended up taking elaborate notes and it took me A WEEK to get through the CD's!
Both the manual and the cd's + manual package can be bought on leews.com (you can't buy just the CD's (alone), but you can but the manual alone.