Excellent question - and I am a little embarrassed to say, like you, I have probably spent around AU$600 in the last couple of months.
AND I've only just started
vaping in that time! BUT I'm loving the whole Vaping experience...
After 35+ years of smoking regular cigarettes - this is a fantastic, interesting and satisfying alternative for sure!
Being a hopeless 'gadget man', the array of vaping hardware and accessories appearing on the market fascinates me.
SO after much research (love doing that!) I presently have a Provari V2.5 and also just got a ZAP (which I haven't even used yet)
BUT I also 'just' pre-ordered, and paid for, a rather expensive GG Ithaka (?!)
Go figure.
I guess I just love this whole (new for me) vaping thing - the very positive 'community' aspect really works for me too!
Final comment: I actually prefer the vaping style to regular ciggies - Brilliant!