Thanks BJ, but that appears to give conflicting information (like much of Giffgaff.)
At
http://community.giffgaff.com/t5/Blog/Half-price-goodybags-lets-keep-the-momentum-going/ba-p/28941/page/3#comments vincent, giffgaff community manager, says two different things in his reply to Nathan and to sloz.
No, you can set your goodybags to recur every Month, which means you buy one the moment your previous one runs out. But you can't buy a goodybag up front.
Yes, it's still half price if you buy it from excisting balance and you can also queue a half price goodybag. (essentially buying two at half price).
Looking for an answer to this, I have found a possible explanation.
The
Goodybags terms and conditions say the following:-
You can purchase a goodybag with a credit or debit card, or from your airtime balance.
If you already have a goodybag, you can purchase another one with a credit or debit card. This will start once the current goodybag expires.
So my reading of this is that you can 'queue' only one Goodybag, as BJ says, (not plural as in NS's post), BUT you can only buy your current one using your balance, the extra one has to be paid for by a fresh money subscription.
This is a bit disappointing for those with large payback credits who might have wished to use their balance to buy both!