This morning I ended up pulling the trigger and cancelled my Telstra account. Between my mobile account and the 4G "hotspot", I was paying up around $109/mo and I've hardly used it at all! Sabriena's on Telstra prepaid, and she gets free calling and all that shit.
So I decided to go in and get my number ported across to Telstra prepaid. The lady who looked after it for us acted like it was weird to go in that direction, but I've asked Telstra multiple times for a deal somewhere around the $30 mark and they basically couldn't do anything.
Porting my mobile number to prepaid was reasonably painless, I think it was down for about 15 minutes. Shifting the 4G over was more problematic.
It's apparently telstra's official position that you can't use post-paid Bigpond gear on Telstra prepaid, but apparently the tech guy there knows a thing or two - he successfully managed to do something to my Sierra Wireless AC760S, and it's all sorted. I think at this stage I'll probably just go with the $50 recharge because that'll last me a whole year if I keep on not using it.
So at this stage I'm saving about $75 a month, which I can't really sneeze at.