OP will probably use a little over a Tank so probably close on R700-800 for fuel. As for
Toll Fees
De Hoek = Heidelberg – Villiers R36
Wilge = Villiers – Warden R50
Tugela = Warden – Frere R53
Mooi = Frere – Cedara R37
Mariannhill = Key Ridge – Paradise Valley R8.50
Total - R184.50
So a Rounded estimate of about R1000 for one way...