Hi guys,

For my school project I need to make an estimation of how much it would cost to implement an online multiplayer mode into a game. It needs to be low-latency and have skill-based matchmaking. Since I don't know anything about programming or networking, I hoped someone could help me out. I'd like to know what tasks need to be performed in order to get this up and running and also what would be the approximate costs of these tasks.

Thanks in advance.

This Questions can't be answered in a simple way, because it depends on many things. You may get a better answer if you answer the following questions:

1. What type of game? Ego-Shorter or turn based strategy?
2. How may players should be able to play? 1on1 or thousands like in World of Warcraft?
3. Should all these players be on the same map? or just like diablo 3, ther can be thousands of players be online at the same time, but only 4 within the same game.

There are certainly more points which will matter, but that can be discussed once you have fixed the above asked paramteres.

I'll do it for three million dollars. Might be less, depending on complexity and platforms.

The best way to get where you want to go, is to build the game using an engine that already supports multiplayer, and then use the platform for matchmaking.
So, for example, if you build your game on the Unreal Engine 4, and then host on SteamWorks or Xbox 1 or PlayStation Network or Google Play or Apple Game Center, then you can use the built-in multiplayer support of Unreal, and the built-in match-making of the platform.
There's still work to be done (your game loop/activities must know that things happen on the network) but it's much, much easier than building it from scratch, or trying to add it to an existing game in some engine that doesn't support multiplayer.

To get a flavor for what multiplayer development is like on Unreal Engine, check out these video tutorials:
https://www.youtube.com/playlist?list=PLZlv_N0_O1gYwhBTjNLSFPRiBpwe5sTwc
Even if you're not interested in Unreal Engine in particular, it may give you a bit of the flavor of the tasks.
Note that this tutorial only goes through the "what you should do" once -- you then have to do that for each and every thing in your game (anything you throw, blow up, plant, ride, steer, control, in any way.)
But that's still a lot simpler than also having to build all the code that Unreal does for you under the covers.

Thanks for your replies. That information alone has helped me out greatly!