The days of grabbing cheap bulk oil are over. A 10-quart box of Kirkland Signature full-synthetic motor oil, which historically retailed for a bargain-basement $30, has skyrocketed to $58. More concerningly, Costco has implemented a strict two-box-per-customer weekly limit. Name brands aren't faring much better; a six-quart case of Mobil 1 is currently sitting at $44, with purchases capped at five per member to prevent hoarders and scalpers from clearing the shelves.