I recently bought a 2 bays Buffalo NAS, which costs RM295 without hard disk. HDD that I bought was 1TB 64MB cache for around RM170.
The reason is that I need a reliable backup since I was quite pissed with Dropbox which deleted my important files silently, given that I enable many devices with dropbox, some of them might be deleting the changes that being done on another machine with dropbox demon (at least, from what I suspect. Shouldn't it just commit the NEW changes instead? I am not sure).
This beast, considered cheap, since there are more expensive, enterprise level NAS out there.
Anyway, this box enable FTP,SFTP and SMB by default so you might be happy with that. But for me, I love rsync, and I need root account to do that (don't ask why, this is proprietary device anyway). There are people out there who documented their Debian/Gentoo experience but I might try that later since if anything happened that bricked my device, the warranty is void.
Anyway, to tell you the steps, in summary
1- Get acp_commander
2- Use acp_commander to change your device to emmode
3- You need Windows or Mac unfortunately to "flash" (I hope I'm using the right term) the firmware. As of the current firmware, v1.54, we have to create the /root/.ssh/authorized_keys from the machine that you intend to login..
4- Using LS_UPDATER, push your custom firmware
5- You should be able to log in using your root account
I managed to use rsync and enable NFS.. which aren't by default. So far so good. But I think for normal user, you might want to try another NAS out there.. seriously.