PEN American Center auctioned off a copy of Underworld hand annotated by Don DeLillo on December 2, 2014, hosted by Christie's. The New Yorker has a short item on it by Stephanie Lacava (Nov. 29, 2014), with additional photos of annotated pages and some further comments from DeLillo. The winning bid was $57K.
"My editor was waiting for the manuscript - and I kept telling her that I was working on a new first sentence. I kept writing it and rewriting it and there must be a record of this somewhere in the archive - but would these pages be located in box number one or in the last box?"Back to DeLillo's Underworld.
"I knew the story could not end with the baseball game and I would soon know, importantly, that the narrative had to leap ahead, roughly forty years into the future, and then work its way back towards the 1950s. This is what made the novel, this was its shape and function."