ST. PETERSBURG — Rays owner Stuart Sternberg said Thursday that progress continues to be made on a new stadium. But many questions remain, including when the stadium will open, who will pay for it and even that the planned Ybor City site might not be the only option.Addressing the media before the Rays season opener at Tropicana Field, Sternberg said the team will remain in the Trop for at least the next four or five years. After that?"Either here or somewhere in Tampa Bay," Sternberg said.Sternberg reiterated that a new stadium likely would cost around $800 million, but added that the price could go up with each passing year. Last November, Sternberg told the Times that the Rays would be willing to chip in $150 million, but said again Thursday that the number was just an "estimation" and a "signpost." Sternberg said financing is the largest issue for a new stadium."But that's yet to be determined," Sternberg said. "A large part will be put on the business community. I put a number out there and it sort of shocked people. We could basically put anything we want out there. I try to be realistic and I try to tell everybody as I see it."Using the New York Mets as an example, Sternberg did bring up one scenario in which the Rays might be willing to pay more. The Mets received $25 million a year from Citigroup for stadium naming rights."If somebody wants to walk in with $25 million naming rights tomorrow my number of $150 (million) goes up dramatically," Sternberg said. "So, yeah, I'll get you to $400 (million). You get me $25 million a year in stadium naming rights and get me to $400, I'll go halfsies."As far as where, the Rays and Hillsborough County have agreed on Ybor City as a preferred site for a new ballpark. But there's still a long way to go before a shovel is put into the ground there, or anywhere.When asked if he was confident the area would help pay for a stadium, Sternberg said, "I'm not confident, I'm not certain, but I'm optimistic."