I was thinking of this more in a modern context of current plans for 11 Destroyer sized ships and 20 of 2000t.
Regards,
Massive
Crewing is what is really expensive. While the purchase cost is significant, think of how much you have to pay on average everyone on a ship, how much you have to spend on training that person, etc.
Which is why I think the AWD hulled frigate replacements are reasonable investments over something smaller. They can do the air defense, and other combat missions. You then have a huge drop in cost and crew to operate the next tier down, the off shore patrol vessels.
The Armidales take 25-29 crew at 300t, where as something like BAM ship, can make do with 35 crew for 2500t. While I think BAM is too big/too expensive for the RAN (unless a high/low was adopted), the actual running costs would not be wildly different and the capability would be huge. These ships could take (up to) most of the missions the Anzacs currently do. Thus freeing up our 11-12 surface combatants to train and operate as intended, not chasing whales.
Obviously with the Damen 2400 ordered it looks like we will go for a mix of several 2400t ships (lets say 6 specifically replacing the Huons, Leeuwin) and then let aim high and say 14 Damen 1000 (or 1400). The smaller ships only require 30 crew to 60 on the 2400.
Possible future ran
6 AWD (3 Hobarts, 3 Hobarts+ with 9.0)
6 AWDlite (AWD hull with updated CEAFAR/AUSPAR/Saab same 48 cell launcher)
6 Damen 2400 (fitted with Ceafar/Saab? 76mm?)
14 Damen 1400 (20mm only but can deploy UAV or Helos also has a slip way that can deploy mini-LCM/RHIB)
3 LHD (no other landing ships, money/crew from the Heavy landing ships diverted to buy 3rd LHD - Patrol boats take on Landing ship tank missions which is more about aid, troops and light vehicles)
1 LSD (We keep Choules)