Annie, I think it really depends on the person, with the idea of "extravagance." I have a tiny car that needs to fit my tent, weights, tables, displays and all my work. I'd like to have 4 or 5 dress forms to bring with me everywhere, but I just don't have the space, so I've had to to get creative. I bring one with me and use wooden hangars to display my cowls, which really don't sell flat, because you can't tell what they are or how awesome they will look on.
My display is really minimal, but I do have work at lots of visual "levels." With textiles, it's important to keep my display simple, so that the work stands out. If you have smaller items, your display itself needs to be seen from several paces away. You also need to show your own aesthetic when designing your booth. Your work and your booth design need to make sense as a whole. It's a mini boutique just for your work.