I work on Sundays and Saturday I wonder if Carrara markets will be ok
Haven't been to those for years, you could try.
Don't forget that there are lots of organic/local co-ops around, you know the pay your $40 and get a box of produce type ones.
Our local IGA also buys local fruits from specialty growers, ie Dragon fruits from the farm here in Canungra.
I think the first step us to start questioning your store managers where their stuff comes from.
Buying ethically isn't always as tricky as you think.
Eating local and seasonal can be pretty restrictive though.
Having said that, growing veges is great fun and if you have the room for two small chooks or even a couple of quail. It's surprising what you can do yourself.