Now Goodwill prices everything at certain price points (long sleeved shirts are around $4.50, sweaters $5.99 etc.), plus on the 1/2 off color of the day you spend 1/2 of that so you can find some gently used, or new clothing for a fraction of what you would pay for it retail.
I have found quite a few button up shirts that can be worn with leggings. These shirts are so incredibly comfortable and worn with boots or flats they are absolutely adorable! Or at least I think so but I do love them!
This is a black and white plaid one I found. I think this is from New York & Company.
This one is actually better worn with jeans but for lounging around the house it is fine with leggings.
p.s. Please forgive my picture quality. I was doing a self-timer shoot and did not focus on my face. Also you will notice the same bottoms for quite a lot of the pictures as I did it all on the same day 