I made my bridesmaid bouquets with hydrangeas from the grocery story. $5 a stem and each flower was so big I only need 3 per bouquet. So $15 for each one! They were super easy to make and looked great! (I think they looked nicer than mine)
You can always use fake flowers. My stepmom & her mom made my bridesmaids their bouquets. I order my bridal one from etsy. I don't like real flowers so I wanted fake ones for the wedding. & I agree that they are expensive, just to die. Here are pictures of what they look like:
My MOH, one of my bridesmaids, & I just did my flowers with flowers from Hobby Lobby and Carolina Pottery (I'm in SC). We bought lanterns at Wal-Mart and attached flowers under the hooks using florist foam then did a ribbon loop to carry them. We found fairy lights to put inside instead of a candle. I'll try to attach a picture, but I'm on my computer right now, and the pics are in my phone.
Order real flowers for you and your MOH, but use silk or fake flowers for everything else. Etsy has great options for this but make sure you check the return/exchange policy in case you don't like them in person.
Have you considered skipping them altogether and doing one fantastic Bridal bouquet? Don't feel the need to follow a tradition that either doesn't make sense for you or is out of your budget. I don't even have bridesmaids! Or if you have a theme sort of going on, try to work that in. For example, for my evening fall wedding, if I had bridesmaids I might do small lanterns with fairy lights instead of boutiques, or maybe small pinecone bouquets that I could easily make on the cheap from Hobby Lobby!