There's lots of things to consider. Looking at one of the biggest salary surveys in the industry from 2014, you can start to get a clue on what you need to pay when setting up a team in the US or EU. There are cheaper locations but it really depends on what you're doing and how you want to do it:
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From experience I can tell you, that in the end every team costs about the same. Teams from a different cultural background will introduce additional overhead and friction that will even out with hiring a dev from your region. I just assumes you're from US/EU, no offense.
If you want work-for-hire developers/studios, you can basically add 50% on top of the salaries to get a good feeling for the rates to cover the studios other expenses, warranties and margin. Most (serious) studios will not work on a rev-share alone. All games start as good ideas but in the end, only 1% really makes its money back. And everyone has ideas. It's the execution that counts and if you want to get something truly great, you need experienced devs and a budget 3x what you initially thought it would cost, because you will iterate the hell out of a game to make it great.
How long will it take you and how many devs do you need? That's the real question. As you didn't produce a game yet (presumably), you'll very likely underestimate the effort - greatly - that is required! Best is to share your idea with as many people as early as possible to get feedback and a better impression of the effort to realize it. Noone is stealing ideas, again, execution/team is what counts.
I'm 15+ years in the industry, 10+ running my own studio. You don't need to trust me on this, but you can