It's 100% possible to get a really decent new or used D unit truck for under 60 grand. I bought my first expediter, a used '95 FL70 for 35 grand almost four years ago and I'm still running it now. Keep in mind you get paid the same mileage rate wheather you have a $30k truck or a $100k pimper. If the $30k special is reliable, guess what? A lot more money in your pocket and less on truck- It's about getting the job done and there are trucks (that don't look fancy) for under $60k that are dependable if taken care of half way right.
Things I would consider must have's on a D unit are air ride (customers request it a lot), so the unit will have air brakes too. Rear dollies are a must also. Get a lot of straps, pads, and e-channel locks. Due to the changing climate of expediting, I recently added a pallet jack to my box make life easier, but that's not a must.
If buying used, it may be best to go through a dealer that will offer some kind of warranty.
-Weave-