I'm attempting to export a quick fan-edit from Sony Vegas 10 and I'm trying to find a good preset. Exporting a 3 second clip to an AVI using the YUV 720p 50fps preset at draft quality yields a file of 329mb - what is the best preset for rendering large files with an "OK" video quality while not having the file size be extremely large?

I have looked at changing the bit rate but it appears grayed out for AVI files.

Apologies if the solution is obvious,
John