https://www.energy.vic.gov.au/safety...ing-swer-lines
The exec summary puts the cost of HV power underground at $168K / km. So start at about 40K I’d reckon and work up from there.
Also. The electricity poles will 99% likely be on an easement (look at your title) in which case this stuff about wayleaves in the UK is meaningless. And good luck fighting it in court even if it isn’t listed.
https://elringtons.com.au/2011/08/ea...s-for-dummies/