Hi Richard,
I will answer this in detail, so that others may also understand the equation. Of course my objective is to get company for the trip as I want to do 2 full days in Mara while usual tours are only 1 full day.
I have done quite a bit of research and come across similar deals. The following is usually the approx. costs breakdown:
3 days park fee ($80 x $30 = $240) : Since the park fee is on 24 hours basis, the effective days in the park, after travelling will be 0.5 Day 2 Days 0.5 Day = 3 Days. So lets say $ 60 a day
Camping accommodation just outside the park gate, hence about $10 per person for pitching tent. Park camping fees (usually $ 30-40) will not have to be paid.
Food will be cooked by the tour operator's representative, hence food may cost about $10 a day.
"renting sleeping bags?, please!" I beg to differ here Richard. Although right now the priority is budget, given an option I would any day be in a tent rather than lodge/permanent camp. It is definitely much more authentic. Although, you may prefer artificial luxury, it is a personal choice.
So, $80 a day covers your food/accommodation/park fee, the rest $65 goes to the tour operator for fuel, car, their "lower resident" park entry fees, etc. and of course their profit.
I have come up with this equation after talking to several tour operators. And most of these tour operators were recommended by Lonely Planet and other experienced posters.
I'm surprised though, that this is new info to you, as I see you very active in Safari related queries!
Regards,
Sushil