You get 4 large chests, building, bucket and door rights, (If I forgot anything, tell me) and I split the property 40/60, in my favor. Cost is a deposit of 300r and a monthly fee of 250r. After two months, if you were good, you get your deposit back.
Because I don't need it and I needed money. But I'm not selling it anymore, because I became Gold so I now have 3 residences (2 maybe?) one of which being on utopia, and also I get lots of many now.