Thanks to these two deals you can get a $300 gift voucher for 200 and spend it howveer you like.
https://www.ozbargain.com.au/node/436903
https://www.ozbargain.com.au/node/436628
Hopefully it can be combined with a site wide code if one comes along, since the voucher is a credit in your account.
Nah - I bought redbaloon vouchers on gumtree before and they don't stack with any other promotion.