With activation of a new 2-year contract, Costco offers the Apple iPhone 5s 16GB Smartphone for Verizon in Space Gray, Silver, or Gold, or for Sprint in Space Gray, Silver, or Gold for $57.99 with free shipping. That's a $20 drop from last week's mention of the Verizon version and the best outright offer we've seen for this iPhone. (It's also a current price low for either carrier by at least $42.) It sports an Apple A7 processor, 4" 1136x640 Retina display, 8-megapixel iSight camera with 5-element lens with f/2.2 aperture, True Tone flash, and 1080p video capture with 30 fps video shooting (120 fps shooting at 720p slow motion playback), 1.2-megapixel FaceTime HD camera, Touch ID fingerprint reader built into the home button, M7 motion coprocessor, 802.11n wireless, Bluetooth 4.0, and dual microphones.

It's also available for AT&T in Space Gray, Silver, or Gold for $77.99 with free shipping. That's tied with last week's mention and another all-time low for a new unit. (It's a current low by $122.)