what are the differences between wired and wireless NAS? Which one is better?

[Shivam15]

Also what is the most cost effective way of building one?

 

[R_1]

cost effective? or cheapest?
wireless will always be slower than wired, wired simply has more throughput. wired on the other hand you have to pay for each connection. (Buying the wire and switches)
wireless would be cheaper as you would need no wires but then again you would be limited by the wireless transfer link, which a nas can saturate.
wired tends to be more reliable.