2005 Suzuki Forenza pulley

Hello, how much should it cost to replace a pulley in a 2005 Suzuki Forenza? My mechanic estimates about $700 due to the labor involved in removing the “top of the drive train”. I’m not at all knowledgeable about cars. I live in central Illinois (Midwest, small town market). Something under the hood is noisy, and my mechanic (who I believe to be fair and trustworthy), pinpoints it to a bad internal pulley. He says I can continue driving on it, but when it gives out the car will stall. Any advice will be greatly appreciated.

“Bad internal pulley” isn’t specific enough for us.

Please tell us what the specific name of the part is.

Otherwise, we can’t form an opinion as to whether $700 is fair.