Oh come on, let's be realistic. You are only fooling yourself if you actually believe it is because they "want" to bust the budget, to put things aside, just to give a "cover the plate" amount. It is absolutely because they feel they have to. Nobody wants to look cheap if they don't follow the standard. I grew up in Saddle River. It was and still is all about appearances.
On a previous thread, somebody said the MOB actually kept a spreadsheet of what people give, giving the thin excuse that they need to reciprocate equally in case they go to their weddings. That in itself is rude. If it was really what people "wanted" to give, there would be no tit for tat and only giving what someone else has given. People would give what "they" wanted.