Well I find it rude that they volunteered to be bridesmaids, especially since they don't live anywhere near you! Then complain about the costs. SMH, that's what a bridesmaid does most time, pay their own costs, and yes it gets expensive that's why it's not something people volunteer for. Ugh.
Your maid-of-honor is supposed to be shouldering the burdens of planning, btw, rope her into it! She doesn't get a free pass. o.O
As for your wedding plans, beachhouse or none, I can't say. I'm not educated enough on that aspect of wedding planning. :/ Sorry.
But for the dresses, go to alfredangelo for them, they have very affordable dresses, an array of colours, and different styles that complement each other. Also alfredsung too.
(I worked in a bridal boutique)