Solar quote Langwarrin, VIC

Looking for some help and feedback on some solar quotes that I have recieved.

I’m in Langwarrin Victoria.

I’m looking to get a system that will help significantly reduce our solar bill. Not expecting to move fully off grid but with 5 people actively in the household and high energy bills, very keen to take somewhere between 50%-70% annually off our bills. We plan to be in our house for at least the next 10 years.

We are looking at a solar and battery system. No EV car yet but likely that will come in the next few years too.

Quotes so far have ranged quite a bit so any input you have would be great. Our average power consumption is quite high with monthly bills up to $500-$600

Also worth mentioning that we have a 15m x 10m shed and we have had quotes for both panels on the roof of the house or the shed. Our preference is the shed. The shed already has power supplied to it so I’m told we wont need to dig new trenches between the house and the shed to funnel power back for battery storage.

I have put the quotes into a spreadsheet and attached a picture of it