Your DVD burner probably came with some software. It may have a "copy disc" function. I use Nero for this and it works quite well.

I dunno about DVDA Studio, but in the full version you can Prepare and Burn separately. When you do just a burn you tell it where the AUDIO_TS and VIDEO_TS folders are. If you have two DVD drives you can put the original in one drive and tell DVDA to use that disc for those folders. It will happily use them to burn the new copy. If you only have one drive then you can copy those folders to the hard drive and tell DVDA to use them from there.