Be careful what you wish for -- setting the minimum wage to half the prevailing wage at a municipality is likely to create very weird setups, especially where a richer cluster is next to a residential or poorer one, e.g. Manhattan and Jersey City.

Bank tellers and janitors in Manhattan would be getting a fortune compared to the same job being done (by the same company) less than a mile away. I suspect the "bonus" jobs will quickly have all sorts of semi-illegal strings attached to them; there will be a rush by employers to reclassify jobs as being done in a poorer area (we do not work there, we are just visiting / delivering), etc.

While the current state has problems, the proposed fix may be worse than the disease it is trying to cure. My 2c.