J&R offers the Canon EF 40mm f/2.8 STM Pancake Camera Lens, model no. 6310B002, for $199.99. Coupon code "LABORDAY" makes it $184.99. With $5.60 for shipping, that's the lowest total price we could find by $8, outside of the price below. (However, it was $3 less in June.) This 0.29-lb. lens is for use with most Canon SLR cameras. Deal ends September 4.

A close price: Abe's of Maine has it for $187.99 via coupon code "DEALNEWS12". Shipping adds $3.90. Note that it is on pre-order.