My personal view:
The more you migrate to higher end rigs, the more sense it makes to buy used. Depreciation is crazy on a mid-to-high-end DP. These also typically have a large laundry list of issues during the first year, which are likely to be resolved in a used coach.
For a class c rig, I would probably go new, rather than used. Depreciation is less (in total $$$$) and you have 100% control over how it is treated from day one. Like it or not, class c units are not built as robustly as higher end DP's, if for no other reason than to save weight.
In any case, IF you decide to buy used, there is NOTHING more important than reviewing good, complete maintenance records and a conducting thorough inspection from top to bottom, before handing over a nickle.
