Maybe highway robbery, but pretty standard in Australia - mobile phones are expensive here. As someone pointed out in another comment, Telstra's standard price

Maybe highway robbery, but pretty standard in Australia - mobile phones are expensive here. As someone pointed out in another comment, Telstra's standard price for off plan data is $2/Mb (for a consumer mobile, not a b2b contract which is presumably what the power company had). For 90Gb of data that works out at $180,000, so pretty consistent with the reported cost.