Newegg offers the Obihai VoIP Telephone / Fax Adapter, model no. OBi200, for $49.99. Coupon code "EMCFFGM26" cuts it to $37.99. (Amazon charges the same with free shipping for Prime members.) With free shipping, that's $2 under our September mention and the lowest total price we could find now by $11. This adapter facilitates real-time fax over IP and supports Google Voice, SIP, and OBiTALK VoIP services.

Update: The coupon has expired at Newegg; however, Amazon still offers it for $37.95 with free shipping for Prime members.