That's the official price in Hungary. They replace the entire lower half of the computer, so you have to almost pay for a new computer.
Of course if you go to a 3rd party repair place, they will order a genuine Apple battery and simply unglue the old one and glue in the new one, for the price you say. Apple won't do that because they don't know how to repair the things they create.
[doublepost=1504280897][/doublepost]So I called Apple and they said that if the computer is out of warranty (which it is) then there is nothing they can do. They confirmed the price and told me I would be better off with a 3rd party repair, which would cost far less. I asked them what if it explodes, having heard that swollen batteries can explode. They just repeated that if it's out of warranty, they can't do anything.
I'll wait until it gets really bad then I'll get it replaced by a 3rd party. So far the computer is running fine, it's just bulged at the top and bottom, but it doesn't interfere with much. Yet. How likely is it to blow up?
don't take this chance... it will break stuff if it keeps swelling. just replace the battery or remove it entirely and live with the slower speeds.