yeah I know what you mean, apple's adapter costs
$79 bucks for the 60W!
Here is where I got mine; The MacBook Pro's use the 85W btw.
$32.99 85W Adapter
Here is also a 60W adapter, it will also work, it is cheaper, but it will take longer to charge up your computer, but if cash is tight.
$26.99 60W Adapter
Sure beats full price, and they are fully compatible. It came with a 1 year warranty too

I recommend apple batteries, they are expensive but they perform way better than like almost any 3rd party. You can look for a reputable ebay seller, let me know if you find a good place for replacement battery, mine is at 3/4ths its life, i'm getting worried.