Oh yeah, pashut. I was assuming everyone had already done that one since it was a free $10...
Plan A - Exxon
Two audio books a month (four total) plus $10 credit towards full price for each additional book (ie, probably only one more), then ~$15/mo.
Plan B - IHG
~$1 for unlimited audio and physical books for two months, then $10/mo.
Bottom line: If you only get four audio books and don't want unlimited kindle for two months, then Plan A, otherwise Plan B is a no brainer unless I am missing something.