The answer to the question "how much does it cost to make a game" is exactly the same as the answer to the question "how long is a piece of string". Whether a budget is high or low is relative to the amount of time given, and resources required to complete a task.
In project management, we talk of managing the magic triangle. You have to manage time, resources and money. You may have an abundance of one, enough of another, but seldom plenty of all three. A good project manager will try to balance them to create an even and stable triangle.
Code:
TIME
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/ \
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RESOURCES(people)------MONEY
If I gave you a budget of $2000 and 2 months to make a single player card game with relatively static graphics, simple rules and few animations, that would be a HIGH budget game, and I believe, achievable, due to the ease with which it could be accomplished by a small team.
If I gave you the same $2000 and 2 months to create the next 3D multi-player shooter, incorporating complex physics, where every item shown can be interacted with, destroyed, manipulated, and would span 1000 levels, that would be a low budget game, and would probably fail.
Now, given $1M and 2 months, you might hire a legion of artists and programmers to tackle individual parts of the game. That is a high budget game.
Just my 2ยข. Collect the whole dollar!
Mark