I can throw something together in a little bit for a dedicated.
EDIT:
Haha, turns out I already had one. Let me just test it to make sure everything still works.
(It uses Randy's dediSave support function, so major credit to him for that.)
You set the following prefs in the server.cs file (not good to change while its running):
1) Save interval - In minutes, and this should be self-explanitory.
2) Number of backups - It will save up to x files before deleting the first one it saved.
3) Save base name - The save file name, before it is suffixed with the save's ID.
EDIT2:
All set.
http://www.willhostforfood.com/users/T/Truce/Script_AutoSaver.zipDefault savings for the preferences described in the last edit:
1) Save interval - 30*
2) Number of backups - 50*
3) Save base name - AutoSave_
*Since Bisjac requested the script, I used the settings he expected.