I think this is a better solution. I see your point about base building. I think a VIP class or prestige class that allows one to have more props would solve the issues that builders are facing while still being fair to other players.
Although, might be hard to implement. If someone joins the class, builds, and changes jobs, do their props disappear?
-1 this is as corolla said pay to win and it may make players happy but at this point in time not only is the prop limit sufficient at this time for building as unless you are building something cool (at which point you might need more) you need maby 45 props. So I think it would be more efficint to make a building class with a custom prop limit that CANN'T base because that would provide an unfair advantage