The cost to build former President Barack Obama’s Presidential Center rose to more than $615 million through the end of 2024, according to the latest filing from the Obama Foundation, the non-profit created to build it. That is more than double the $300-million estimate when the center was first contemplated in 2016. It alleges discrimination against the minority-owned firm based on correspondence from the engineer critiquing its experience and quality of work. The latest construction cost estimate was included as part of the foundation’s annual report on its fundraising and spending, which the organization released in early September. The center, originally set to open this year, now is expected to welcome visitors next spring.