What? Only "socially important jobs" could buy the cheaper apartments? What the hell
And usually, with few exceptions, socially acceptable jobs are the ones which pay little compared to the effort they require, and also compared to the (non-monetary) value they bring to society. You also want these people in your city because sure it's great that you have tech workers, lawyers and bankers, but who is going to be in the hospitals?
Society or your local town won't collapse if there's not enough web developers but it may do if it lacks firefighters.
In other words, rents will just increase. The solution is to build 300 more apartments, and make them available at the bottom of the market, not the top.
I do wonder how did similar scenarios worked out historically?