Do any of you have stations called "Circle K" near you? They have a "preferred customer" price that, in this area, is 6 cents lower than their normal price. They charge the same "normal" price for cash, credit, or debit transactions. The "preferred customer" price is because they are electronically tied in to your checking account and deduct it directly from there themselves.
BTW - a couple of stations I saw this morning were back to $2.999 while two others (one a Circle K) were at $2.989 and $3.089 and those two were less than 1 mile from each other.