We transitioned from a popup directly to our 40ft diesel. Although I love my motorhome, there are tradeoffs. For me, camping in the PU was more fun in some ways(and much more total sleeping capacity) but traveling in the MH is no comparison... its waaaayyyy better. Especially if you're on the road for a long trip where you will need to overnight on the way. Much more convenient and comfortable in every way.
If your budget is $70K I would suggest your purchase price be no more than $60-$65K. I guarantee you will have a "to do" list, and it will take some $$$. In fact, your MH will become a perpetual to do list of big and little fixes and upgrades. Budget accordingly.
When I was looking I did extensive research. My budget was $50K. Although I actually had some RV sales guys laugh in my face when I told them I wanted a diesel for $50K or less, my final purchase was 20% less than my budget and I got what was a top of the line unit, just 15 years old at the time. That said, many of the amenities in my MH are still on par with much newer MH's with the exception of slides. So, depending on your wants and needs, you can find something to suit what you are looking for.
Good luck in your search.