I am going to keep this post short and sweet. Here is my pick of hardware, (What I feel is the best bang for your buck) for a home server. I will put together a $400 base build and I will list some extra's you might want to pick up if you have the cash..

CASE $30: APEX PC-389-C Black Steel ATX (no frills case, had to go cheap... but there is plenty of room for modest upgrades down the road...)

PSU $40:  Rosewill Stallion Series RD400-2-SB 400W (400w may not seem like a lot but this should handle our system just fine. You could even upgrade to a middle-weight graphics card down the road and be ok)




MOBO $105: GIGABYTE GA-880GMA-USB3 AM3+ (more expensive than what I would normally spend on a mobo but it has an AM3+ slot on it which means you can upgrade your proc in a year or two to AMDs hot new "bulldozer" processor line which is coming out in about 6 months. Furthermore, the onboard GPU is beefy enough for at least some light gaming. You won't be running Crysis 2  anytime soon but World of Warcraft should be okay...)

MEMORY $70: G.SKILL Sniper 8GB (2x4GB) (the cheapest 8 Gigs of memory I could find, and you can add another 8 gigs later on)

PROCESSOR $115: AMD Phenom II X4 925 Deneb 2.8GHz (my original idea was too buy a dual core phenom and unlock the other two processor but this is a much more stable option. Plenty fast and 4 cores is great for a server...)

HARD DRIVE $40: Seagate Barracuda ST3500413AS 500GB (cheap and 500GB is "enough" storage for now, if you have the extra cash, buy two more of these drives. Having 3 separate drives would be great for running Virtual Machines later on)

Total Price (all prices above include shipping costs): $400 exactly :) - So not quite "under" $400 but close enough.


Have an Extra $70 to throw at this machine? Here are a few proposed upgrades...

PSU $50: FSP Group SAGA+ 400R 400W ATX12V (same output? hardly... FSP Group makes some of THE BEST power supply units. This product should be stable and run for years to come. Not to mention it can handle a heavier load than the PSU in the first build, even though they are rated the same...)

CASE $50: Xigmatek ASGARD II (for only $20 more you get about $50 more in features. Much nicer looking case, tool-less, great cooling, still a budget case with a few drawbacks but it is an extremely nice case for the price...)

HARD DRIVE x2 $80: Seagate Barracuda ST3500413AS 500GB (Don't buy a bigger hard drive, rather add a second identical hard drive... You have several options if you do this... If you leave this computer to be a server and want more security, you can make the 2nd hard drive "mirror" or be an exact copy of the first. That way if one drive dies, you have a second backup/exact copy. If you want more performance, you can "stripe" the drives, this makes them behave like 1 physical drive with 2x the data throughput. Finally, if you want to use virtual machines on your server, splitting them up across two hard drives will give you much better performance than just sharing one...)


CONCLUSION:
So that is my current recommendation for building a low-cost server for your house. Things that aren't included: a monitor, keyboard, and mouse. All of which you will want to purchase if you later decide to make this a regular, extra, desktop computer. However, in the case of a server, after the initial setup, you can simply "remote" in. I am assuming/hoping you have a monitor/keyboard/mouse in your house you can "borrow" for a few days to do the initial setup. After which, those things can be returned to their original owner :) as you will be able to access your server from another computer. You CANNOT game remotely on a server. I will just point that out now. You CAN game on a server operating system, but you need to be directly connected with your own Monitor/Keyboard/Mouse setup.


One Other Note: I am in no way associated with Newegg. I personally buy most of my computer hardware from them because they are a great vendor and do a great job of handling returns, which is rarely necessary. None of those links above are affiliate links or anything like that and I encourage you to shop around as you may be able to find better prices for components on sites like Amazon or Tiger Direct.