I'm four years away from retirement eligibility and I dove in head-first. A deal presented itself and I went for it. I'm learning along the way, but I love challenges and I love learning new things.
As for your personal situation, I would only advise that you do your research on floor plans and know what will accommodate your family's needs. You are going to be sitting/sleeping in it much more than you'll be driving down the road. As for the age-old question about diesel vs. gasoline? I have a gasser...I'd love to have a diesel, but no more than I can use it now, (with still being employed full-time), the extra costs were not justifiable for my budget nor for my travel needs. The quickest way to kill a diesel engine is to not use it. You can find some really nice gassers out there that will more than adequately do what you want and will be lesser expensive to maintain in the long run. So my advice is don't limit your options on what's available by only looking at DPs.
Good luck to you! And for the record, I say GO FOR IT!!!