To valuate your company after three months you have to take two things into account:

A) How much value will you have created be the end of three months?

B) How much value will you still be able to create?

If you only have enough talent and ideas to last you for three months, you don't get funded. And if you think you'll have nothing done by the end of three months (but will still have talent and ideas), you also don't get funded.

And if you're able to create something of great value after three months but you'll still have lots of value left to add, then just unask the question because the answer is irrelevant.