Participating councils (Vic):
Baw Baw
Casey
Cardinia
Greater Dandenong
Knox
Manningham
Maribyrnong
Monash
Merri-bek
Mornington
Yarra Ranges

The prices vary by council. They also ship to the rest of Vic and AU, but the prices aren't subsidised, just slightly discounted (no idea if the non-member location pricing is actually competitive with Bunnings, etc, or not. This isn't my area of expertise)

Shipping is covered if your council offers a discount. Shipping costs extra elsewhere, so most likely not worth it. They also seem to offer free pickup from Langwarrin.