HAVANA — José is an eager almost-entrepreneur with big plans for Cuban real estate. Right now he works illegally on trades, linking up families who want to swap homes and pay a little extra for an upgrade.

But when Cuba legalizes buying and selling by the end of the year — as the government promised again this week — José and many others expect a cascade of changes: higher prices, mass relocation, property taxes and a flood of money from Cubans in the United States and around the world.

“There’s going to be huge demand,” said José, 36, who declined to give his last name, stepping away from the crowd and keeping an eye out for eavesdroppers. “It’s been prohibited for so long.”

Private property is the nucleus of capitalism, of course, so the plan to legitimize it here in a country of slogans like “socialism or death” strikes many Cubans as jaw-dropping. Indeed, most people expect onerous regulations and already, the plan outlined by the state media would suppress the market by limiting Cubans to one home or apartment and requiring full-time residency.