What is Server Farm :
A server farm is a collection of computers that work in conjunction, or in parallel, with one another. Server farms are an implementation of distributed computing.
One of the largest, if not THE largest server farms, is maintained by the popular search engine Google. At last report, Google had over 10,000 computers in its server farm. The picture shows an example of a server farm with several hundred 1U rack mountable computers.
Cost Estimation :
You should sign up with Google or Amazon for a cloud server or several, and scale up as you need capacity (and actually get players). Even at a large scale of 25 or 50 large servers, each of which could easily handle 1000 connected players or more if you use node.js, you’re still spending less than buying and co-locating your own servers. It’s a large difference in money spent, probably 5-10x.
Let’s consider the scenario though, hypothetically.
A high-end server today costs about $2000 USD, and co-location in a serious datacenter is about $100/month per server, so that works out to:
200 x $2000 = $400k capital expense
200 x $100/month x 24 months (usual minimum contract) = $480k hosting
Roughly $900k USD, not counting your costs of setup, delivery, etc. In your world, they only support 150 players each, so that’s:
200 x 150 = 30k users
You’ll need to charge each player $30, just to BREAK EVEN on the hosting part. If they’re willing to pay you $60 (highly unlikely unless you are a AAA game), then you’ll make a profit, unless you promise to support them beyond 2 years, in which case you won’t.
Let’s look at the cloud/scaling scenario, with a higher per-server number assuming some asynchronous server software like node.js or websockets:
One xlarge server for 24 months on AWS: approx. $4500
1000 connected users = $4.50 cost per player for 24 months
Huge difference in cost and scaling ability. I’d note further that you are unlikely to have every player connected all the time, so you can safely have probably 4000 players on one server, with a maximum simultaneous connection rate of 1000 players. That brings your cost down to around $1 per player. A lot more profitable.