We are made up of many shapes and sizes. It is far better to have a dress that flatters your body shape than what might be in style now. A bad fitting dress will not do you any favours. The correct fitting undergarments can take an ok dress into a fabulous dress. A simple dress can look amazing with the right jewellery and shoes. Floaty and sparkley is not necessarily going to win you Belle of the Ball. Colour looks fabulous so try and think outside your normal colour range. You may well be surprised. Many many times since being in business have I heard "I don't do red" and many times they have ended up hiring a red dress.
Internet buying: If you want to risk buying the cheaper dress off the internet then be ready to have a back up plan. I have had people rushing in at the last minute because:
1. Their dress hasn't arrived. 2. Its a different colour to what they ordered. 3. It doesn't fit. 4. Its not the style they ordered. 5. The style doesn't suit them. 6. Its poorly made and doesn't hang properly.