This is a "small story" as SF adventures go. He runs a tramp freighter. She's stuck in a go-nowhere job. Together they hope to find some advantage. No kingdoms are not won or lost based on their bets, and that's exactly what makes this such a compelling story. There's nothing in the story that guarantees success, making failure a very real option every step of the way.
As novels go, this is solid, unfluffed, chewy SciFi, worthy of its own made for TV movie. While some parts of it are archaic, most of it still stands up.
Because the book is so short, the character stuff that might seem fluffy in a big book doesn't feel like fluff at all. In this book, the internal dilemmas of the characters work as substance. Their flaws add complexity. They mismatched goals add conflict. And trust, trust is in mighty short supply.
"If they only trusted each other, they would sort this out immediately," you'd say. Yes, that's exactly right, but you can't buy trust at the docks, and certainly never in bulk.
I'm giving this one lots of stars and a rare "recommend" for anyone who likes space opera, noir, or space cowboy stories.