We charge $24.95 for an L-O-F and customers get every fourth one free. My experience with lower priced or free oil changes is that every tight-wad in town comes in but never spends a dime on anything else.
We charge $5.00 for rotation but often give it away. There are several tire store outlets in our (small) town who don't charge for this service so I hate to be the only guy in town who does ! Pretty hard to convince a customer that we can rotate tires better than the tire store and "that's why we don't do it for free" !