To me, containers are secondary to what's inside of them. If you arrange flowers, you probably have a favorite vase (mine is a gravy boat) but I think a bouquet can look gorgeous in just about any vessel.
Like condiment or mason jars:
Or drinking glasses. The colors of this plastic cup perfectly matched this bunch of gerbera daisies:
Or any other household vessel, like my favorite gravy boat:
My point is, cool containers help, but they don't need to be expensive to show off a naturally beautiful arrangement. Use tea cups, tin cans (put a container inside to prevent rusting), cookie jars, creamers, beer bottles. I actually like a little contrast. A beat-up vase filled with elegant flowers like roses looks interesting, and draws your eye in. Likewise, displaying a rustic-looking bunch of wildflowers in a sleek, modern vase. A contrast of styles can turn an ordinary handful of flowers into something surprising and memorable.