Filesystems, Disks and Memory

Hi all
i'm looking for good advice regarding backup plan becuase its first time to me handle large scale database expected to grow up 10000 - 20000 record per year with daily operations on it
I'm working as sysAdmin in educational organization ( junior level ) with mixed OSes environment including ( win2k3 - win2k8 - Linux -Unix Solaris Sparc & x86_x64 ) mixed RDBMS form different vendors including ( MS SQL Server - MySQL - Oracle ) mixed network infrastructure from different vendors as well as the hardware of servers .
In brief the core layout of my business is as follows:-
1- a dedicated web server serving business logic as webbased interface (only 1) as the clients of it will be few .
2- a dedicated database server serving only at most 2 databases beside system databases ( for now its SQL server 2005 in near future we will migrate to oracle ) and the main database initial size is about 1 GB for now it holds just dummy data for testing purposes .
its expected to grow up 10000 - 20000 record per year as i think all records are just text and numeric fields as i guess there are no BLOBs but i'm not sure .
3- backup devices are as follows entry level DAT drive with max size of 36 GB in native mode and red ray DVD drives .
and there's no budget for now or for the near future to buy new expensive storage .
the operation on data are daily ( 6 days per week 8-10 hours per day it's needn't to be up and online 24/7 for now ( daily data retrieval - daily data modification )
what should i do to put a good backup plan for 3 years from now and forward .
should i employee something like freeNAS or Openfiler or just getting enough with offline backups on tapes only also i want to decrease downtime in case of disasters as the dependency on the database will grow up day after day .
I'm looking for a tip in putting a good backup plan.
sorry for long
thanks for your helpful souls

2 Things:
1)
For that you will have to burn some DVDs with an OS image or bootable DAT...
You need for it to go fast the full OS with backup/restore utility you use...

2)
We dont know your volumetry... 20.000 records of 1 kb isnt the same as 5 Mb...

If you have no budget for backup/restore you cannot plan DR and so, who will be blamed once the disaster occured?

I would look for a little backup device that does deduplication, I saw some less than 5000 $ that can hold almost a TB...

Thank you

Overland has some interesting very small appliance:
Data Backup, Data Protection Solution, Data Protection Software, Data Disaster Recovery, Snapshot Software: Overland Storage
like:
Overland Storage : REO 1550

I suppose if you search a bit, you may be surprised by the choice and pricing of what can be produced today...