Predatory pricing, also known as undercutting, is a pricing strategy in which a product or service is set at a very low price with the intention to achieve new customers (Loss leader), or driving competitors out of the market or to create barriers to entry for potential new competitors.

https://en.wikipedia.org/wiki/Predatory_pricing

I should have called it "price gouging" or perhaps "profiteering".

https://en.wikipedia.org/wiki/Price_gouging

There isn't really a great word for long-term exploitation of an easy structural advantage, though. Landlords don't have to form a cartel, since (a) everyone has to buy from them, (b) land is limited in supply and (c) the barrier to entry is high. Maybe it's a "natural cartel".