Although I would love to buy a server someday they are simply not cost effective to run for a gaming community. The parts you have chosen (although great) are more for a desktop PC - you would need a different mobo and case for sure as well as 32 - 64GB RAM. Oh and some more HDD/SSDs so you can run in RAID 5. That would raise the cost to easily over $1500. Then you have to rent space at a datacentre and pay to have the server located there (this is where the different case comes in). You have to pay the shipping fees and fitting fees. Most probably you lose access to the server at this point and now have to pay maintenance fees to call out an engineer if there is ever a hardware fault. Consideration would have to be made for a backup server and monitoring programs as it's now our responsibility. We lose the freedom of migrating hosts and are now locked in. We also lose the freedom of upgrades which at the moment we do once a year. So although the monthly costs would be less we are still paying for board, bandwidth and maintenance events with the risk of huge one-offs for hardware faults.
Love the idea just not practical. Although I do have a set of 5 rackables servers at home which are fun to play with