1950's ranch SFH, rewire and plaster walls

[Ryan K.]

Looking to rehab a 1950's rancher, it needs to be rewired due to the old existing knob and tube wiring. It also has original plaster walls in decent condition. I was originally thinking a full gut job in order to make it easier to rewire, but considering the walls are in good shape would it be easier to save them and have the electrician just fish wires through wall (which adds to the electrician labor)? Both the crawl space and attic are wide open. 3 bedroom, 1 bath, approx. 1000 sq ft total. Any opinions on which method would be the most cost effective?