The redevelopment of Wimbledon Centre Court, which includes a retractable roof, is understood to have cost £100m.
There has been speculation that the translucent roof cost between £1m and £20m, but a source close to the project said that the overall development was "about a factor of 99" greater than the former figure.
The budget is so high because the development does not just include the roof, but also structural supports and new facilities, such as hospitality suites.
The source said: "About £100m is the right ballpark [figure]. Some people have guessed figures on the scheme thinking that the roof is just a finite extra, but you have to include all the facilities and constructions supporting that development."
The revamped centre court will host its first matches at an exhibition tournament later this month. Former world No 4 Tim Henman joins husband-and-wife stars Andre Agassi and Steffi Graf in matches to be played on 17 May. Kim Clijsters, the grand slam-winning former world No 1 and former girlfriend of Australian Lleyton Hewitt, is also due to take part.
The players should not have to be wary of hitting high lobs – the roof is 16 metres above the court. However, Henman, Agassi and Graf can expect a bigger audience than when they last played at the All England Club, as the redevelopments include 1,200 extra seats taking the capacity to 15,000.
The roof has been designed by Populous, the Kansas City and London-based architects formerly known as HOK Sport. The company is currently working on a masterplan to revamp the Australian Open tournament in Melbourne, and are perhaps best known for their collaboration with architectural giant Lord Foster on Wembley Stadium.
Melbourne are trying to hold on to their status as one of the four grand slam tournaments, the others being the French and US Opens. Their contract as a major tournament runs until 2016, and the Populous masterplan is part of a near-£1bn business case commissioned by the Victorian government to keep hold of the event.
Reports from Australia suggest that Sydney is keen to host the Open, although the tennis boom in the Middle East means that both Abu Dhabi and Dubai are pushing for grand slam status. The masterplan is expected to improve infrastructure at the Melbourne tournament, and include a faster retractable roof for the rebuilt Rod Laver Arena.
A spokesman for the All England Club declined to comment.