Walmart offers the North States Bat House for $20.43 $20.59. (Amazon charges about the same.) Opt for in-store pickup to dodge the $5.99 shipping fee. That's the lowest price we could find by $2. It measures approximately 8" x 5" x 15" and features wood construction, three compartments, and a bat facts label.
Update: Amazon offers this item for $20.40 with free shipping for Prime members.