I found a place even more trashy and more fun than a thrift store! The Garment District in Cambridge opens a bale of clothes every day, dumps it in a big room, and you get to climb and swim in the mounds of junk and pay only $1-a-pound for what you find. Seriously.
Lincoln seems to think its the greatest place in the world! I usually leave with a big bag of things I rip apart for the fabric, trim, and buttons for under $2. And for the entertainment of watching a rolling, tumbling toddler playing in a room of laundry? Priceless.