My parents want me to find a way to setup a server in our house that will connect to the network and allow us to back up all of our home computers(about 2tb of data) for under $400. I would also like to be able to use it as a testing webserver, but thats just if I can for the price.
What would you recommend for that price range? The main priorities are keeping the data safe and allowing some revision history and keeping the budget as low as possible. I can build it myself if its just parts and setup.
Thanks in advance for any help

PCPartPicker part list / Price breakdown by merchant / Benchmarks

CPU:  Intel Core i3-3220 3.3GHz Dual-Core Processor  ($119.99 @ NCIX US)
Motherboard:  ASRock H77M Micro ATX  LGA1155 Motherboard  ($69.99 @ Newegg)
Memory:  PNY Optima 4GB (1 x 4GB) DDR3-1333 Memory  ($16.22 @ Amazon)
Storage:  Seagate Barracuda 2TB 3.5" 7200RPM Internal Hard Drive  ($89.99 @ NCIX US)
Storage:  Seagate Barracuda 2TB 3.5" 7200RPM Internal Hard Drive  ($89.99 @ NCIX US)
Case:  Rosewill R379-M MicroATX Slim Case w/300W Power Supply  ($49.99 @ Newegg)
Total: $436.17
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-01-20 22:31 EST-0500)
That is one I was looking at, but its a little high for my price. I have no parts sitting around that would work for this unfortunately

EDIT: for this I would use intel's ability to have different parts of the hard drive have different RAM setup's. I'd have RAID0 for the OS and RAID1 for the rest of the data

So you need like a NAS type of thing?  I need to do something like this.  You should post what you decide on doing.  Have you heard of free NAS ? You can use that for backups and stuff but I doubt you could host a website on it.

Try to get some parts of old pcs off ebay that are good but cheap.

IDK, it was just a general suggestion, I know that p2 got to christmas a old server that isn't in use anymore and which was like for free but is actually rather good