Oak Leaf via Amazon offers its Oak Leaf 40-watt Incandescent Filament Light Bulb 6-Pack for $16.99. Coupon code "S5K7VHBK" cuts it to $13.99. With free shipping for Prime members, that's $1 under the best price we could find for the same quantity of similar bulbs elsewhere. They measure 5.9" long and feature premium tungsten filament and brass basses.