TP-LINK RE355 AC1200 Wi-Fi Range Extender for $59.99 shipped. Here is a screenshot for reference. The TP-LINK AC1200 Wi-Fi Range Extender connects to the router wirelessly, strengthening and expanding the router’s signal into areas it can’t reach on its own. The device also reduces signal interference to ensure better Wi-Fi coverage. Most places have it for about $104.