I wonder when we get closer to opening if anyone in the Japanese media reports the budget on this expansion because I'd be curious to know. Back when Super Nintendo World was planned to open in summer 2020, Nikkei had reported that the budget was 60 billion yen, which was $545 million at the current dollar : yen exchange rate.
I would expect DKC to be quite a bit cheaper than the initial Mario land. Although the boom coaster is a pretty innovative ride system they're doing for this, and it's reported to expand the Nintendo area by 70%.