I too was looking for low cost NAS devices for home use.

When I was looking for on-line prices, I looked on Amazon's website.

Amazon has reviews. Of the NAS devices I found on Amazon, each one had multiple reviews talking about issues with the devices. Each had problems I considered serious. Some had hardware problems - disk drives failing. Others had operational issues where they would up and fail under high network utilization (like you get with large file copy operations). Still others could not be configured to match the capabilities listed on the box. Either the configuration user interface sucked so bad the user couldn't work through it or the boxes lied.

Read the reviews before purchasing.

You may want to wait until better units are available. I'm waiting.