There are things which survive centuries like walls, and then stuff that slowly disintegrates and is a proper nightmare to change/replace - plumbing, electric wiring, general room layout with those thick structural walls, size/layout of windows etc.

I can guarantee you that electric wiring from 1970 is something different than that from 2010 (personal experience, sockets slowly failing).

Old apartment/house is definitely an additional maintenance cost and possibly tons of other inconveniences, and should be priced accordingly.