Yes, tire prices change daily, faster than the stock market. Really stupid. They were $34 yesterday. $50 is a 47% increase overnight.
Edit: WM still lists for $34: https://www.walmart.com/ip/Westlake-RP1 ... 3/55180284 They are always price fixed to Amazon to the penny. Likely (delivery by) Amazon sold out and those higher prices are from marketplace affiliates. As soon as Amazon raises their price, so will WM.