Traveling options to Maun:
1. Fly with Air Botswana from Johannesburg to Maun direct, every day of the week. This is the fastest and easiest, but also the most expensive.
2. Rent an AVIS rent a car and drive yourself, just make sure you can return the vehicle here in Botswana. I'm not sure what this will cost you.
3. Buy your own car in South Africa and drive yourself here. VERY handy to have your own wheels here, but not a necesity as the local taxi service is very reliable and safe.
4. Jump on a bus from Johannesburg to Gaborone (Botswana capital) then from there catch a bus from Gaborone to Francistown and then onto Maun. This option is the cheapest option but will take you around 18 - 24 hrs to arrive in Maun.
Weather this time of year:
It's HOT and just getting warmer everyday, besides the occasional isolated thundershower in the afternoon, its HOT.
Expenditure on a daily basis:
Not sure, as this depends from person to person. Maybe some of the other chaps can help you with that.
See you all soon!