Friends make fun of me for having a wealthy GFWatch this thread
Additionally, if you're destined to stay with these friends, rise above them. Maybe don't say anything to them but instead acknowledge to yourself that you are NOT going out with her for the money and that you love her for what she is besides her wealthiness and therefore your friends are wrong. Give them a neutral look or state at them and possibly then they'll realise how hurt you are as you're not taking any of their crap, but also not being aggressive about it or feeding into them. Sure, they're probably not bullies but like what other options are there?