From link 2: "However, a significant portion of the human genome had already been sequenced when Celera entered the field, and thus Celera did not incur any cos

From link 2: "However, a significant portion of the human genome had already been sequenced when Celera entered the field, and thus Celera did not incur any costs with obtaining the existing data, which was freely available to the public from GenBank". The reason Celera was able to finish the project cheap was because public funding had already done the first 90%.