It's so hard to say what value a certain performance increase has, since it's very much a matter of opinion. The BDP-93 is an overachiever for its price range, as is the BDP-95. If you're really not sure, you might get a BDP-93 and use the 30-day return period to try it out and decide if it makes you happy. If it does, you're good to go. If you still feel an upgrade bug, return it and switch to the BDP-95.

I will say that getting a BDP-93 and a $500 DAC would not be as good a solution as getting a BDP-95, mainly because I suspect that any $500 DAC you find will not be as good as the BDP-95 (probably not much better even than the BDP-93) and will only be useful with CD's - there's no way to feed digital audio from Blu-ray, DVD-A, or SACD into such a DAC.