I personally never factor in resale value in my purchases, and I rarely buy second hand, because of the additional risk and additional effort involved. In general, poor people do not have capacity for risk.
Personally, I'm able to enjoy the lifestyle I do because I buy second hand. I'm also able to add value by repairing items, although as you say, there is the risk that someone is dumping broken items on you. You just have to be discerning, and possibly experience getting burned a few times.
None of which I factor resell value in.
I keep my vehicles on average for 8 years or more, to the point where resale nill
I have the same couch I bought almost 15 years ago now, if I replace it the old one will not be worth anything and will be donated or trashed
My current computer is 6 years old, and when I replace it will be recyled or donated as well
I run almost everything I own to fail. Even my home, barring economic necessity forcing me to sell (i.e need to move for a job, or economic depression[1]) I plan on dying in my current home
[1]and face it at the rate of government spending right now a dollar collapse is very possible