I wonder if you could book a spot in the gardens at Lanarch Castle one evening?
Given that you're near to New Zealand's only "castle", it seems like an opportunity at least worth giving a try. Would be cool to be somewhere with the castle visible in the background, even if it was in the distance. They have 14 hectares of land.
If the booking fee was under $240, then just charging all the players $10 would cover it.