Just happened to notice that Walmart has a sale right now on Mobil1. http://www.walmart.com/ip/Mobil-1-0W...5-qt./17034374 That's $13.73 for 3qt of oil + whatever filter you use. Buy 3 of those for $68.64 and have your next 5 oil changes covered.
They also have the Extended Protection for $25.47. http://www.walmart.com/ip/Mobil-1-Ex...-5-qt/36019107 $15.28 for 3qt of oil.