Tory Newmyer of Fortune magazine adds up the potential costs for those who want to win the next presidential race.

The Republican presidential primary is already shaping up to be a sprawling free-for-all. More than a dozen potentially serious contenders and counting have already joined the scrum—popping up in early states, snagging operatives, and wooing donors. But only a handful will still be standing a year from now after the first burst of contests. Surviving will require, among other things, a little luck and a lot of money.

Just how much? The answer comes with an elephant-size asterisk, since so much of what determines the outcome is unknowable. Consider the involvement of Super PACs. Those loosely regulated outside groups rattled the GOP’s 2012 primary by empowering a few billionaires to prop up the bids of moribund candidates who exhausted their own resources. They’ll play an even greater role this time around, tipping the playing field unpredictably. Nevertheless, the pols angling to carry the torch for the business wing of the party (think former Gov. Jeb Bush; his protégé, Sen. Marco Rubio; and Gov. Chris Christie) must cobble together a daunting number of four-figure checks for their official campaign organizations simply to meet the competition’s de facto ante. To put some hard numbers on what it takes to get through the first four states (the only ones on the calendar so far), Fortune surveyed leading party strategists, fundraisers, media consultants, and the historical record.