Jerry Colangelo's plan to build a glorious, open-air baseball stadium in downtown Phoenix has Norman King sitting somewhere in the infield.

King, proprietor of King's Onion House, is a 34-year-old farmer's son who has run a produce operation in an almost-historic building at 425 East Jackson for seven years. He had heard rumors of a downtown stadium, but didn't learn until last month that the ballpark might be built on top of his 70,000-square-foot onion house.

"I was a little shocked," says King, one of a handful of people who own property in the footprint of the proposed stadium. In the days since the November 10 announcement, King has begun to casually explore his options. Though he says he hasn't spoken with government officials about his future, he's scouting other locations and thinking about what his suddenly important Jackson Street property might be worth.

The Onion King has also picked the brains of realtors who have asked him what he's up to. "What do you think is gonna happen?" he'll ask them.

Trouble is, no one--not even sports potentate Jerry Colangelo--knows for sure if the downtown stadium will come to pass.

An upcoming vote by the Maricopa County Board of Supervisors on raising the sales tax to pay for the stadium is just the first of several large hurdles the project faces.

The deal also depends, among other things, on whether Phoenix is awarded a major-league franchise and whether taxpayers will revolt, forcing a public vote on the stadium project.

Then there is the pesky problem created last week when developer John F. Long offered to give the county 60 acres of west-side land for the stadium. The move could save taxpayers about $100 million but flies in the face of Colangelo's desire for a downtown ballpark.

If all the dominoes do fall the right way, King and his neighbors will have to go. And while the public may assume that landowners like King are poised for a financial bonanza, nothing of the sort is guaranteed.

For now, stadium-site landowners can only guess how they will fare if negotiations for their land begin in earnest. And, more important to everyone else, Valley taxpayers can only wonder how much they will be expected to cough up for the deal.

In theory, landowners at the proposed site should get no more than the current market value for their land. In reality, fair market value is in the eye of the beholder. The actual, final cost of acquiring the land will depend on which side--the landowners or the county--negotiates most effectively.

The experience with America West Arena--the last time government condemnation power and taxpayer money were used to build a home for a Phoenix sports team--proved crafty landowners can profit handsomely from hardball negotiating.

Colangelo wants the proposed Phoenix ballpark next door to the arena, the taxpayer-built Purple Palace where his Phoenix Suns play their home games.

The land in his way includes active businesses, run-down structures already bound for the bulldozer and property whose owners would be just tickled to sell.

The most prominent of the property owners--in land ownership and power--is Phoenix Newspapers, Inc., publishing parent of the Arizona Republic and Phoenix Gazette. The largest structure in the stadium's path is an R&G newsprint-storage warehouse that essentially became obsolete last year when the papers moved their printing presses to suburban plants.

The newspaper company owns the entire block on which the warehouse sits, bounded by Fifth and Sixth streets between Madison and Jackson.

Colangelo's field of dreams would also displace the Yount brothers, Robin (a major-league ballplayer destined for the Hall of Fame) and Larry (a former minor-league pitcher turned investor who's been riding out the local real estate crash for the past few years). The Younts, operating under the corporate name Y&Y Partners, bought most of a city block about a decade ago. Their land is now occupied by vacant shells that once held skid-row bars and restaurants. Though the Younts and other property owners in the area claim to be uncertain about having to divest their properties, the R&G's corporate mind is made up: It's rarin' to sell.

"I'm sure the value will be greatly enhanced by all the things that have been happening--the arena and so forth," says R&G public relations voice Bill Shover.

Not surprisingly, the papers have been strident in their editorial support for the new ballpark since Jerry Colangelo called a press conference to announce his preferred site. The papers' let's-break-ground-and-quickly editorial stances are troubling some keenly interested observers.

David Therrien, a pioneer in the recent downtown-resettlement movement by the Valley arts crowd, is suspicious of the proprietary interest in the downtown stadium deal held by the state's largest newspapers.