Overstock.com offers the Furniture of America Nicholas Enzo Contemporary Tufted Leatherette Futon Sofa in Dark Brown, model no. IDF-2100, for $452.49. Add it to cart and click through this link to drop it to $398.19. With free shipping, that's tied with last week's mention and the lowest total price we could find by $144, outside of the price below. It measures 36.5" x 76" x 36" as a sofa and 21" x 76" x 47" as a bed.
A close price: Amazon charges $402.46 with free shipping.