Thrift stores or libraries where I can find cheap used books?

Hey guys, I stay in the woodlands and there's a disappointing amount of used book stores in my area.

I'm curious if the Houston/Midtown area has a better selection or more options? I'm primarily looking for used books ranging from 99 cents for paperbacks and $1.99 for hardbacks.

Any suggestions are welcome and if you know of any frequent library sales that would be just as helpful!