I don't want to move my HDDs much, as it would definitely result in one of them one day dropping and fail... also, they are not portable (there are many), and inconvenient to use with a laptop.

So, this is what I merely need:- 1) ability to access files as if the HDDs are directly connected to the computer. Which means I don't have to "transfer" to use (more like stream), and ease of access. 2) low cost.