This one seems like the best value. It has a filtered plug so it is ideal for plugging in directly to your router.
These TP-Links devices are a good value as well. They offer more options:
Refer here to TP-Links product FAQ: http://www.tp-link.com/en/article-406.html
$30 used you still get Prime shipping. | 3 for $40 used | With wifi for $44 used | This one is only $25 used for a pair of single port devices. It’s not as fast at 200MBs, but if you’re just connecting to the internet that’s plenty.