Very good question, it's a tough one. With new technology (new DAC's, multiple DAC's in parallel, SACD & DVD-Audio, etc) coming out more and more, buying new may get you more for the same price as used.
I suppose it really depends on the specific used model you get. Wadia's have a tendancy to sound great, no matter which model you get; but even then, there are clear improvements in the newer machines vs. the old.
My personal approach was to buy the cheap Sony NS500V SACD/DVD/CD player, and have Ric @ EVS mod it. I get sound quality better than most players up to, say, $1.5k, for 1/3 to 1/2 the price. Then, when the next big thing comes, I know I haven't spent too much now for very good, though not superb, sound.
Perhaps buying a quality used product would get you to the same point: a temp solution for not a lot of money right now.
And just to add some more to the confusion: see what kind of deals you can get on new or almost-new equipment right here on Audiogon ! Kind of the best of both worlds.....
Lot of luck,
Todd/Chams_UK
PS - while I think they are all very good, I would not recommend Meridian CD players at this point, nor ARC. Maybe the Meridian DVD's, they are newer technology, and will most likely play DVD-Audio. But software is scarce, so that may be less improtant.