So i'm sure i am not the first person to suggest this, but i had to make a post about this subject.
Currently there are very few houses/business available for sale, and those who are on the market are really overpriced, the Real Estate market is currently too high, and the by adding new houses and business could help adust the prices.
Business: New business, like clothing stores, tattoo shops, new gas stations would add a lot of new perspectives for players to invest their money, and it could also boost other jobs like Trucker (more deliveries).
Houses: Adding more houses would be a plus, but also there are currently a lot of houses that aren't simply used, example: i have 2 neighbours where the door is unlocked (for over 2 months now) so it's probably someone who rarely plays but are occupying a house that could be used for active players.
(the fact that the player connects once every 30 days shouldn't give the player the right to keep their properties, and i'm sure that's the case for many houses currently unlocked).
By lowering the market it would also benefit the RP on the server, since people wouldn't have to grind as much to have nice stuff.