Opus 4.5 is significantly better if you can afford it.

They also recently lowered the price for Opus 4.5, so it is only 1.67x the price of Sonnet, instead of 5x for Opus 4.

There's a counterintuitive pricing aspect of Opus-sized LLMs in that they're so much smarter that in some cases, it can solve the problem faster and with much fewer tokens that it can end up being cheaper.

Obviously the Anthropic employee advertising their product wants you to pay as much as possible for it.