If they reply that they need to know your revenue, expenses, number of sales, etc., before they can even guess at a number, then what? Do you give them your financial info? Or do you stick to your guns and ask them to come up with some number by themselves before you engage with them at all?
This litmus test will tell you which it is. If their number is reasonably high, they know it will be hard to get into your space. If the number is low, they just want to poach employees.
There is zero value in talking to them without a number you like on the table. You must defensively reduce the information asymmetry in any way possible.
Anchoring negotiations to your business value and not the synergic value of your product in their offering is a mistake, usually.
So no they don't really need your economics. Also, if they came to acquire a company without knowing the cpany worth or without it being part of a bigger strategy, chances are they're the bad kind of corpdev