Is there reason you are think specifically of ACE or FR3? For example, do you need the drop down bunk? Or is it the lower price point of new models? ,Or something else?
If you are set on those models, I might try to find a used one with lower miles than the one you cite. hopefully it would have decent resale value for you a year and 20k miles down the line. If you are not set on those models, perhaps consider other low-mileage used ones from reputable manufacturers.
I'm a newbie,too, so take my thoughts for the little they are worth. As I shop for a used Motorhome, I might not be attracted to 3 year old unit with almost 50K miles. Somebody planning low mileage trips might be attracted to it, but that restricts your pool of buyers.