Having been through all this more than once since the 1964 Gun Control Act when we all thought we would lose our guns, I'm no longer scared by alarmist rhetoric. I lived through a major ban, I fought it, and I'll live to fight the next one. I'm not a quitter and I've got the Constitution on my side. Me and the Constitution don't give up so easily.
So I don't envision anything changing drastically after the election, but to answer your question:
All pre-ban lowers became HIGHLY valuable (in fact, way way way ridiculously over valued) during the 1994 ban. If you fear a future ban, your strategy today is to buy 5 or 10 stripped lowers now and keep them for the ban. Then sell all but one at hugely inflated prices and use the money to build your dream rifle.