skripka: The tuition point is addressing a separate issue.
The entire lifestyle, not just the homes, of MO Jews (not heimish yidden) is based on materialism. You can see the open differences between, say, Brooklyn/State Island Yidden and Teaneck/Five Towns Jews.
Why do you think MO Jews, generally, have such small family sizes whereas traditional Orthodox Yidden, typically, have large family sizes?
DaMoshe: Yes, it is well known that MO schools don’t negotiate significantly lower tuition rates whereas traditional Yeshivos do.
How many times have you missed a “Kiddush Club” in MO shuls? Not too often. Then they come home shikur. This issue is extremely rare in Yeshivish/Chasidish minyanim.
If you have 8 kids in MO school (in the imaginary world where an MO family has 8 children) and your income is $60k/year, you’ll be paying most of your income to the MO school, if you want a chance of keeping the 8 in MO schools.
lakewhut: It is true that the SY families in Flatbush often have fancy houses, but by the Ashkenazic Yeshivish families (Flatbush, Kensington, Bensonhurst, Boro Park, etc.) that is infrequent.