Is it Islamically permissible to demand exorbitantly high alimony?

It is generally observed that exorbitantly high mehr/sedaq/alimony are set as the condition for marriage by the bride (or her family who represent her). This thing has the potential to set forth the idea of marriage primarily for the sake of material benefits rather then spiritual ones, coupled with the possibility of breading social wrongs and disrupting it's very fabrics, cynicism etc. Although, the wife has the right to get her alimony. But is it permissible to set forth demands, in the prenuptial, so exorbitantly high that marriage tends to become a cause for bad rather then good? Is there a suggested/advisable alimony that should be demanded?