I've been working on having some balls to value bet on the river. Here is an obvious case. He doesn't have spades, unless it's QsTs, and this is highly doubtful. He doesn't have a higher set. So bet it. I'd say $30 or so.

And either limp in or raise to $2 I would say. I've found some occasional uses for preflop minraises, but EP with 99 isn't one of them.