it's not the food as much as the time.
you're spending a day, sourcing, prepping, cooking @ their place, entertaining them (or not).
Last dinner for 8-10 guests was a 4 course, two hors deuvres, salad, entree/veg, dessert. $1100.1 cook & 1 waitstaff
There was a minimum amount they could not go under, in other words if there were only 4 guests I'd still make $$$$. You'll have to figure out what that means to you and set a minimum that works for you.
I've cooked a 3 course lunch for 5 and charged them $125 pp, didn't make sense to charge less....
Cooking for 1 or 2 takes almost as much energy as cooking for 20+.
That's why personal cheffing at cost plus supplies just does not work for one person. At least that's my experience.
cooking with all your senses.....