Same offer which expired yesterday. New offer good till 4/12/2018.
I did the offer in store yesterday and noticed the rebate is good till 4/19/2018. I believe the offer will extend for another week
Costco Wholesale via Membership Wireless.com is offering their Samsung Galaxy S9 or S9+ Smartphone for T-Mobile promotion for "Buy Two Samsung Galaxy S9 or S9+ Phone and get $680 Back via Prepaid Card when you add a new service line" valid at participating Costco Warehouse only [Warehouse Locator]. Thanks comfortably-numb
Note, pricing available only in Costco Warehouse only. Device and carrier selection may vary by location. Qualifying credit, new line, qualifying service and full-price device purchase required.
Costco Warehouse Member Exclusive Offer Price
Samsung Galaxy S9 for T-Mobile
$679.99 (+ taxes and fees)
Samsung Galaxy S9+ for T-Mobile
$799.99 (+ taxes and fees)