We had these floors put in (oak) just 10 years ago and have refinished them once in that time. Now we really REALLY need to move , and in order to sell this house, we need to refinish the floors. Please help with any advice and if you can answer these questions:

The floors are oak, there is a seriously dark traffic path from one door to the next in the entire downstairs. Will sanding and just re-polying help, or would we need to stain it? If so, what affordable (cheap) stain, poly do you suggest?

Also, our dogs (alway the dang dogs) peed on a chair leg when they were puppies and we went out of town. When we came back, there was a DARK DARK DARK circle around the couch leg, about a foot wide!! I've tried everything to clean it, and it's clearly a permanent stain Will that disappear when we sand it??? UGH! It's right in the middle of the floor!

Sanding and finishing floor should get rid of the gray in the traffic areas, the dog stain may sand out but it probably needs to be cut out and replaced.