How much you can make will depend on to many factors for people to give you a usable value.

Theoretically you could make millions, then again less people get rich from making games than people who play lotteries.

How much you make will depend on how you make money, adds in game purchases and the price for playing the game is all a factor.

A bad game with 1000-2000 player should make a $0.1 a day.

A great game with 1000-2000 players should make $10-$15 a day.

The thing about games is that the leading games get most of the money while the otters fight over the table scraps.

If you plan on making games for a living you will have to dedicate your life to making games, a good choice if it was your plan from the start.

Give a scale such as

$0------------------------------------------------$$

You could make anywhere from $0 to $$ (NOTE: Line not to scale)

It is impossible to say how much you would make. You could end up in debt as the running/advertising/website costs are more than the income or you could end up the next notch.

The reality is that it will probably be the former!

You need money to make money.

Without at least a million dollars for marketing, it is unlikely to make more than a few hundred.