> For example you need to maintain it, make sure there is no wild foliage, people don't start camping

You really don't. Dirt lots coated in rusty chainlink, gang tags, weeds, and tents are traded hands all the time, even in Downtown Los Angeles, for top dollar. Maybe you hire a crew to weed wack once a month if that. Even land zoned for a single bedroom bungalow goes for a lot of bread, because one day in the future that zoning can change and there is always demand in a big city with a lot of jobs near a major harbor and airport for more units, and parcels in big cities are finite.