I won't post this as a deal as the Coles 20% off voda recharges was already posted but this took some working out so it may be helpful to someone.
I needed at least 1GB a month for 12 months and this seems to be the cheapest way possible at the moment if the voda networks works for you (it is fine for me).
You need the $29 prepaid mobile broadband startup kit (the $2 won't work). I got this at a voda store, they wanted ID. This gives you 3GB for 30 days.
Buy a $125 recharge from Coles, they will say it doesn't exist thats because for some reason its called $125 electronic pin rather than mobile broadband which the other MBB recharges are called. It is in fact a $125 MBB recharge (the docket shows this). These are on special for 20% off for another week so its $100.
The recharge comes with 6 months expiry, use it on the 29th day after you activate the $29 MBB kit. Any unused data from the initial 3GB should roll over.
so is it 30 days + 6 months = 7 months?