I don't think things are going to get better any time soon, as in rising home prices. If interest rates start going up again with the economy improving, houses will stay at the same price or less, as monthly mortgage payments are going up.
That said, I am with everyone else here - you should finish before sale. It never is easy working on something you know you aren't going to keep, but just keep chipping away at it and install neutral and medium price materials.
Two times in my automotive ownership have I fixed head gaskets on high mileage trucks only to sell them. With a bad head gasket they were $1500 vehicles. With a new gasket, running great, they were $4000 trucks. I just got in the mode where I knew that my time was worth about $100/h and did it. And yes, on a V8 I only did one side - so you are allowed to take some shortcuts.
George