Dell increasing price on a cart.

Last Friday (June 5, 2024) I wanted to purchase a Dell monitor to complement my Dell XPS I bought a year ago. The monitor was Dell 32 Monitor S3221QS. The price was AUD478.60. I placed the order into the cart.  The next day (Sat 6, 2024) I wanted to finalized the order. To my horror, I found the price in the cart had increased. It now showed AUD576.40. 

I chatted with a sales rep on the website but he was not much of a help. Instead, he asked lots of question unrelated to why Dell did not honour the cart price.

I wanted to know if this is Dell's way of doing things.