Mark,
What are you going to be doing with your truck, if you need a lot of power now then I'd say yes, otherwise I'd wait still some bugs in DMax that need working out, plus not many used ones available to knock the price down.
I think demand/availability is such that most dealers won't deal as they can get just about whatever the market will bear for them, as far as power goes I've driven a couple of them what we can max out a 6.5 to without going crazy dual turbos etc. is where you start with a Max, you can get 100+ Hp more in a Dmax just by plugging in a box,
Word of caution don't test drive one it's addictive I'm struggling with the same decision, my dealer called me he has a new Red 04 just in on his lot, trying to convince me to trade in the 98 6.5 for it.
Tim, 98GM K1500 6.5TD(L56/L65), Heath PCM,3.73 gear,4L80 tr,4" exh,Amz air filt&dual oil flts, Heath remote FSD, TDO-7 clone turbo, Heath fan clutch,mandrel crossover, pilar gage BST/EGT/TRN, remote elec fan tran cool,alum trn pan