D-28's can be nice instruments; the problem is that Martin are now churning out around 70,000 guitars a year so no guitar gets any meaningful individual attention in the critical areas of bracing and top tuning. The result being that on average you'll get the majority being kind of ok, a few absolute stinkers and a few which are positively stellar.

The best way to buy is used; get a nicely played-in 20 year old and let someone else get hit with the depreciation of a new one.

Another issue is that there are many smaller shops doing the Martin thing and doing it so much better; Bourgeois and Santa Cruz to name but two.