WASHINGTON (AP) — The addition of a bookstore and rising construction costs are driving up the price tag of the planned Martin Luther King Memorial.

The group building the memorial raised their fundraising target by $20 million on Tuesday to $120 million. Organizers say the additional funds will cover the bookstore, security enhancements required by the National Park Service and the rising costs of fuel and construction materials.

Also Tuesday, the group announced a $3 million gift from the Bill and Melinda Gates Foundation and a $1 million gift from the John S. and James L. Knight Foundation.

The announcements come as the memorial project was closing in on its initial $100 million fundraising goal. The total raised now stands at $98.8 million.