Is the purchase of lands by the wealthy at high prices, which deprives those with limited income of the ability to purchase, considered a monopoly or religiously permissible?

Buying land is not considered hoarding (ihtikar). Hoarding, in its intended meaning, refers to merchants withholding people's food and sustenance during times of need to raise prices, and it is forbidden if it harms people. Jurists have stipulated that for hoarding to occur, the hoarded item must be food, though some have extended this to include anything people need and are harmed by its withholding. A Muslim must be lenient in their buying and selling, and consider the circumstances of the people and show them mercy.