Why you asking about Mahr if you are not muslim!!!
this condition of Mahr is in Islam & If you need to understand then you need to ask simply not post such a topic & after all you can`t marry a muslim Lady, so if you are not Muslim & Ur lady is not muslim too,so Pay or not to pay it seems you really don`t love her cause it`s not a sale you got a wife from(if you have money then make her happy if not tell her family your situation).