Wanted opinions regarding cake pricing

Vanakkam makkale! So the thing is, I bake as a hobby and I have a team lead's birthday coming up. My team is quite taken with my baking, as I used to bring desserts for potluck and my team lead is quite fond of them too, so they were hoping that I could bake one for her birthday. But they are insisting that it is only right if they pay for it, despite my denials to take any payment for this. So currently, I am not sure with how to uk, charge for the cake as I have never done it before. So my question is : how much would you pay a homebaker for a 1kg eggless butterscotch cake with pralines/caramelized cashews on it?