Are you familiar with that area? Most houses that go up for sale for $1m+ in the area (and all the way into old lakewood) are sold to chassidim.
Are all of them wealthy? No. Are many of them wealthy? Yes.
Can't opine on the demographics and area as I have zero knowledge on that but the fact that expensive houses are mostly sold to chassidim isn't that indicative on their wealth, as it is known that those leaving Brooklyn view the term "expensive" totally different, they compare it to what they'd pay in Brooklyn. This has driven house prices up in Monsey/Monroe like crazy.