I agree about the potency and brilliance of the ending. In fact, it works so well that Kill Fee is one of two Barbara Paul books* I've never been able to bring myself to reread. It's dopey, I know, and I'm really as big a wuss as this may sound, but I feel that I bear a share of the guilt in causing the ending to happen -- by finishing the book and closing it! I just can't stand to make that happen again. Isn't that dumb??!
Howsomever: I did finally acquire a copy of my own, while I was in Seattle. So the Big Blank Spot on my Paul bookshelf is now filled. Only that one early effort to go!
*The other is Good King Sauerkraut, and I suppose the reasons are somewhat similar.