Robert Gordon Orr, OC (born March 20, 1948) is a Canadian former professional ice hockey player, widely acknowledged as one of the greatest hockey players of all time. Orr used his ice skating speed, scoring, and play-making abilities to revolutionize the position of defenceman. He played in the National Hockey League (NHL) for 12 seasons, starting with 10 with the Boston Bruins followed by two with the Chicago Black Hawks. Orr remains the only defenceman to have won the league scoring title with two Art Ross Trophies.

By the time Orr turned 16 in 1964, he was still two years away from playing in the NHL and his father Doug was dissatisfied with the Bruins' treatment of the prospect. Doug had asked the Bruins' Blair for more money for Bobby and was turned down. Doug Orr met Toronto lawyer Alan Eagleson at a juvenile fastball tournament dinner in Parry Sound and asked Eagleson to help out with the situation. Eagleson agreed to work with the family for free and continued to do so for the next two years. Bobby and Eagleson developed a relationship Orr would later describe as being like brothers. The two soon became a team, discussing Bobby's future plans without his father Doug.  Eagleson was determined to get Orr a top salary. When Hap Emms, the general manager of the Bruins offered a US$5,000 (US$37,713 in 2017 dollars) signing bonus and US$7,000 and US$8,000 (US$52,798 and US$58,715 in 2017 dollars) for his first two years in the league, Eagleson countered with US$100,000 (US$754,256 in 2017 dollars) for the two years. or Orr would refuse to play with the Bruins and play for Canada's national team instead, like Carl Brewer. Orr wanted desperately to play in the NHL, but he went along with Eagleson's strategy and was willing to play for the nationals. The Bruins and Orr agreed on a US$25,000 signing bonus (US$188,564 in 2017 dollars), and a salary "less than $100,000" for the two years, a figure kept secret. Speculation has ranged on an annual salary of US$25,000 to US$40,000 (US$188,564 to US$339,415 in 2017 dollars) at a time when the typical maximum rookie salary was US$8,000. (US$60,341 in 2017 dollars) The official signing ceremony was done on Emms' boat, the Barbara Lynn, where Eagleson and Emms had conferred during negotiations.  At the time, it made Orr the highest-paid player in league history. But beyond that, the signing became one of the most important in the history of professional hockey. Until that time, players had been forced to accept whatever NHL management paid in salaries. It was the start of the player's agent era in professional hockey. For Eagleson, it was the start of his sports business empire. Based on the Orr signing, Eagleson would become the executive director of the new National Hockey League Players' Association (NHLPA) and started on his rise to become one of the most powerful men in the sport and business of ice hockey.

Using a quote from the above article, answer the following question: What was Orr's signing bonus?
The Bruins and Orr agreed on a US$25,000 signing bonus (US$188,564 in 2017 dollars),