a "roaring noise" could definitely be from the compressor, but he's full of crap, you can DEFINITELY get a replacement compressor for it. whether it's worth it to replace is a different story.

if you really like it, call someone else. but only if it's a really high-end model, because it will cost anywhere from $400 to $900 dollars depending on who installs it. a and e, where i work would charge about 7-8oo dollars or so.