While I couldn’t find statistics for SD County covering 250K income, I did find Census survey results at 200K.

Just over 5% of SD County households have a household income of 200K or more. Given the normal income distribution curve, at a guess, probably 3% or less of SD county households have a 250K income (compared with 1.5% in the general US population).

If you’re in the top 3% or so of households in a given community, I think you do, in fact, probably qualify as “wealthy”.

I think the issue here is a psychological phenomenon. You can always find someone in an income class significantly above you to class as “wealthy”, which, by exclusion, makes you “not wealthy”. But the truth is, if most people can class you as “wealthy” compared to their lifestyle, you probably are “wealthy” – just perhaps not what those looking up from the middle would classify as “fabulously wealthy” which from near the top of the heap merely looks like “wealthy”. All a matter of perception from where you stand.