It didn't actually come that close. Commercial paper rates went to 8% (http://www.wsj.com/articles/SB122186683086958875), which was not insanely high, historically speaking. And certainly part of that rise was due to Paulson's Chicken Little act.

Most businesses which actually make and sell things would have been unaffected if Goldman, etc. had been allowed to reap the consequences of their terrible decisions.

EDIT: A chart from the Federal Reserve Bank of Atlanta, showing that rates for nonfinancial borrowers were basically unaffected: http://macroblog.typepad.com/macroblog/2008/10/the-commercia...