Early last year I bought 2 cases PU 5W20 at $18-19 a case, they shipped it after a month or two. The price a day after I bought it went to $50.
The 2 cases PU 10W30 I bought at the same time for $16-17 a case wasn't available, 3 months later I complaint when they canceled the order, they credited to my account the difference between their sale price and regular price at local store.
Whatever the price they have when you order will be the price you pay.