Are they?

New Zealand is ludicrous marked up in terms of consumer goods, and I’ve just checked pricing. The cheapest is resistive electric. Then fractionally more is gas. Induction costs approximately double for 4 hobs (for 2 hobs it’s about 50% more than resistive).

If you count installation, both electric options are going to be less expensive than gas. If the big cable needs running for induction, the cost might be similar to gas.

Not factored in, cleaning. My god is induction nice to maintain.

Gas is rare and expensive in NZ, I knew very few people who had it. In NYC every house does. My clothes dryer runs off gas. It’s dirt cheap.

Gas cooktops were very popular and are still common in New Zealand. It used to be legal (within building code) to run a small 9kg gas bottle (BBQ size) under your cooktop in a kitchen cupboard, so very cheap to install. Resistive cooktops were and are pretty aweful.

Gas indoors is now considered a health hazard even with range hood, and while you can still buy gas cooktops, I haven't seen a new build with gas in a long time.

I'm actually so confused about this.

When I was in college, I bought a portable induction cooker off Amazon for $60. It was the best. I could boil a large pot of water in about the same time as the gas stove I had at home. (I never timed it, but it felt basically the same.)

I could have bought four of those induction cookers for less than $250. If I ever built a house (I currently rent an apartment and am stuck with gas), I would at least be tempted to literally do that, instead of spending the money on a "real" cooking range.

Why are full ranges so expensive?

Probably marketing as portable and full range are different markets/consumers. Could also be due to volume. Full ranges might be manufactured at a smaller and less efficient scale. It's also possible that they have better components, are more durable, have more features and more power. Induction cookers can cook faster than gas.