When you're talking about a product like a Tascam 2488 there are going to many more compromises than in just sample rate vs. bit depth. The mic preamps will not be primo quality nor will the build quality of the box itself. These units look fine on paper, but are smaller than they appear in photos when viewed with the naked eye.
I've played live music starting about 25 years ago, but I went to an audiologist lately and he was amazed by the high frequencies I can still hear -and I hear a TINY increase in fidelity using 24bit/96khz --- but not enough to justify the 'almost double' consumption of media. And don't forget, even if you do get a GREAT sounding master on a DVD there's no way to replicate that for mass consumption without throwing a whole bunch of cash at the problem.
If this is your first DAW, buy it and use it creatively and don't worry about what you're missing. If you've got about twice as much money to spend you could go with a computer setup, but that would bring you a whole new set of problems.
