Most outfitters will charge around US$7000 to US$9000 for a 1x1 water buffalo hunt including trophy fee for 5 to 7 days hunting.

2x1 is of course a little bit cheaper.

Some cheaper hunts also exist, eg on station land where lesser numbers of buffalo might exist. Arnhemland is remote wilderness so camps cost more to run there but has more buffalo generally. Also be of course aware that cheap hunts may be cheap for a reason.

Most cape buffalo hunting is Africa is now US$10,000 to $12,000 for a seven day equivalent buffalo hunt so I guess Aussie is a little bit cheaper on average.

Do both!