what country do you live in?
there are a few places that will send you a new copy of linux through the post for only a few dollars/pounds/whatever.
Also, can you not get some DOS startup disk and download that way? or is that not possible? (i don't know so forgive me if i'm being naive)
Re: CDs, yes they all do that. Sopme wear out faster than others, the 'ball park' figure was supposed to be that they have a shelf life of about 20 years, so since they were invented in 1982, we may see some disappointed punters in the next 5 or 10 years.
for music, CDs are a farce. They only make sense when computers come into the equation. Compare a CD with it's 20Mhz limit on analogue frequencies and it's step rate method of storing audio information (plus its 20 year life) with a record. The record stores data in a true analogue form (no step rate), has no upper limit to the audio frequency (thus allowing for truer representation of harmonic aspects of the sound) and has an estimated lifetime of fifty years if treated well...
sorry to rant, maybe you could get linux mail order, that's all i had to say!