replying to my own thread feels about the same as most conversations I have - with myself and in my head
I finally gave up, with the impossibility of finding Amstrad software in NZ, I bought a couple of items off ebay violating my 'NZ only collection' directive. Lesson learned - It's not economic!
One auction $5 for a tape (Super Gran) + $12.50 AUS postage ($11.50 postage, $1 seller charge - whatever that means)
Another auction for 16 tapes $42 + $28 AUS postage.
Well, I actually swapped the post address and sent to my sister in OZ who's coming over here in a while and saved about half on postage, but that still seemed pretty steep. $6.30+$1 for Super Gran, and $13 for the other lot. I thought it wouldn't be too expensive sending from OZ to here, but apparently so, even for small items and I'd be pretty sure I could send a single cassette tape to OZ for much much less than what it was quoted to send here. Within NZ, post anywhere it would have been $2 and $6.50 for comparison
I will update the header post with a couple more tapes now for swaps, but so far no takers on the initial post.