SupermediaStore offers the refurbished TRENDNet Powerline Ethernet Adapter Kit, model no. TPL-302E, for $19.99. Pad your order over $25 to qualify for free shipping.
That’s $43 under the lowest total price we could find for a new unit.
This plug-and-play Ethernet kit uses your existing electrical outlet to create a secure high speed building-wide network.

A 1-year warranty applies, although it’s unclear who supports it.