Apple stuff is always overpriced (accessories, hardware for the most part... not trying to start an argument). You can buy a third party one for pretty damn cheap too.
tell me about it, i'm on my 3rd for my powerbook (the old yoyo one - which has an intrinsic fault of overheating anyway!)
They come in in the UK to about £100 including P&P - ouch. Buy a 3rd party one (google)
My iBook charger died on me, too.
I got a kensington air/car/wall thing for $45. Ask if they have an open one. Get a discount.
Also, make friends with the clerks. They'll give you little discounts if you ask nicely and smile sweetly.