I'll give my two cents, but will address the second issue first.
If DW is not happy with her surroundings, how much joy will you have, or be allowed to have in those surroundings?
On the prices , new you have to also consider the thousands that a dealer will usually add after a price is agreed to. Transportation, prep, PDI, Documemtation, all of these add up. Some states also dont apply sales tax to used (previously taxed) vehicles, that could be another few percent saved. The used private sale has none of these. Also on the private sale you have the chance to find the motivated seller, who is more anxious to sell the unit.
It really becomes a question of time, to find the great deal, usually requires a greater investment of time, in order to save some money. Which do you have more of available is the decision you have to make.