My local ferry system has an electrification project[1]; the current active project is three 160-car hybrid-electric ferries for a total cost of $714.5 million. A NZ shipbuilder is probably more competitive than a US shipbuilder, and details matter....
This article says $200M [2] which is a lot lower than I expected, given it's a one-off and larger (I think) than the WSDOT 160-car ferries.
[1] https://wsdot.wa.gov/construction-planning/major-projects/fe...
[2] https://www.ro.com.uy/2025/10/16/nuevo-barco-china-zorrilla-...
Compared to that, €35m or so for a new modern vessel doesn't sound outrageous.
[0] https://www.morski.hr/jadrolinija-za-7-7-milijuna-eura-kupuj...
The main issue I saw here with the electric ferry was that 90% of the installed generation in the islands uses HFO so we would be charging the ferry with a fuel that pollutes more than the diesel used to run it.