Comment by dokyun
I got a lightly used copy off Amazon, along with "The UNIX programming environment" a year or two ago, probably. They're both fine with only a bit of wear, but I don't think they were ever of a super sturdy binding that would hold up well under heavy abuse.
The binding isn't great, but on my copy the pages themselves are getting brittle. In a few more years if I touch them they will fall to little pieces.