The book now is $10.8 billion. But we already have confirmation (officially) that it could be $27 billion next year. And the next fiscal year starts June 1.
Let's say they get 15% of that. = $4.05 billion. 65% margin after taxes = $2.63 billion. Multiplied by a P/E of 30 gives PPS = $5,635
Of course they will never achieve it. But you asked for the optimistic scenario.