Use the power of "Just one thing", each time you pass by or "15 minutes and I'm done" once or twice a day. It is easy to start when you know you only have to do one thing or do just 15 minutes in there and it is surprising how quickly it works too.
During the winter, I used to dread going into the big living room in our house, it was so cold. But we are getting a wood burning stove in there in a couple of weeks and now we will be able to use that room all year round.
I'm not fond of clutter, and I prefer to keep things neat and clean, so I avoid the areas that are the hangouts of my husband: his den/office and the garage where he does editing. They should be comfortable for him.
Yard sales don't generally make an awful lot. Better give the stuff away, one bit at a time. Once bought, that money is a "sunk cost", you are unlikely to get it back. So forget the cost to put it in the closet, think about space you can reclaim.