I have never had a reed last for a year...maybe it's just me, I don't know, but even when I switch off a lot, reeds that start out good can become not so good very quickly...
and yes, double reeds' reeds are very expensive! I used to buy them from my former teacher for $15+...my teacher at school now gives us free ones b/c we're undergrads...yay! : )
And yeah, plastic reeds suck...I got a bassoon one from H&H when they were going out of business (which is still, I think...haha)...it is crap, I would probably have had better luck making one myself!
