So, I talked to the fiance and he basically told me to do what I want. Called my mom to ask if the money she allocated for the wedding budget could be given to us for a down payment instead. Then my mom began asking me why all of a sudden I wanted to elope and what brought it on, etc. Proceeded to tell her the same things that I had told her prior and how what she allocated was not enough to throw a DC wedding. Sent her a spreadsheet with what we would need financially. Finally after more arguing and discussions on how every girl should have their one day, she caved. She agreed to back off, trim the guest list, and raise the budget. I just have one stipulation..I can't tell my dad.
In the end I'm still not sure its worth it nor do I think that she'll fully back off. I think that my mom would rather spend a frivolous amount on one day than giving me money for a down payment.
We'll see how this turns out.