Ok, I see they are using 2 x SP PRO 48V battery inverters, not the larger 15kW 120V SP PRO. This makes more sense now.
The load table is very good, nice detail, just wondering what capacity the split system A/C is? It must be a large central ducted system to draw 4.5kW?
An off-grid system of this type and size is not an easy job but it does seem to be a little on the expensive side. Although without knowing about the complexity, cable runs, trenching required, etc, it’s hard to say. Does the price include the Federal government STC rebate?
Note, I would personally go with the Powerplus battery option. I’ve been using them for years and had no issues at all. Very good Aussie made battery system