External Storage recommendation questions.

Im in need of some sort of external storage, either a harddrive or a NAS server, but idk what to get.

Price should be reasonable for the security and storage space it gives, so heres what i figured so far for pros and cons:

NAS Server:
+ Bigger capacity
+ Raid option
+ Easily expandable
+ Always accessible via the network (local)

- Difficult to transport (not gonna do that, but still)
- Expensive
- Physically larger
- Consumes power 24/7 (i dont pay for power currently)

Harddrive:
+ Easy to pack away and transport
+ Cheaper

- If drive fails, youre fucked
- If you want larger capacity, you end up with two external backups

What do you guys do? Im not sure what i should do :i
Any advice is appreciated.

It will be used for external backup, as mentioned. For my server and my own pc.