Amazon offers the Marantz Professional Audio Scope Dual-Pattern Shotgun Microphone for Camera Mounting for $11.53 with free shipping for Prime members. That's $2 under last month's mention and the lowest price we could find by $67. It's powered by an internal battery or phantom power with XLR output, features cardioid and super cardioid polar patterns, and includes a windscreen, XLR cable, hot-shoe mic holder clip, and tripod/boom pole mic holder clip.

Update: The price has dropped to $10.89. Clip the 15% off coupon on the product page to further reduce it to $9.26.