I am no expert in bridesmaid gowns, but I do believe there are infinite styles and colors. I didn't realize there were so few tux styles.

Fancy dresses in general are reusable, but I don't believe bridesmaid dresses (or wedding gowns) typically are. I presume even grooms rent their wedding tuxes too?

blue102 said she spent only $800 on her wedding gown. Considering some people spend that much on their prom dresses, I think she got a pretty good deal.