Take your example.

Here, a 400K house is going to range from $4.5K(ish) all the way to $10K.

OTOH, a 900K house may also fall in those parameters. Local gov. here is VERY mis managed and corrupt -- with few people questioning it. So the scale is VERY hard to pin down. Generally, the more inner cities (poor) a county house in NJ, the higher the taxes... That is why a town like Maplewood pays so much compared to Saddle River...

(I know those towns don't make much sense to those people outside of NJ area...)