It may be Amazon’s largest Echo display, but the Echo Show 15 is also thin enough to hang on a wall, and it’s getting its biggest price cut ever for October Prime Day. Normally fetching a cool $249.99, the Echo Show 15 is available right now for just $169.99, an $80 discount that marks an all-time low price for the display. Just don’t expect that savings to last beyond October 12, when Amazon’s first annual Prime Early Access Sale wraps up. First unveiled last year, the Echo Show 15 has a 15.6-inch full-HD display, a 5-megapixel camera for video calls, and–of course–onboard Alexa. A redesigned…