I didnt think of water buffalo as being that "exotic." You don't realize how many people around you have them until you start looking. A lot of people keep goats and the buffalo together. They co-exist well. Even American buffalo which are also good pasture cleaners can be kept with goats. I think the Americans are a little crazier though. Plus buffalo is delicious!
Do a search on Craigslist for buffalo. Prices range a lot. Around here a good mature buffalo will sell for $900-1000. They could be profitable if you Breed them I think. Just have good fences.
Real Buffalo are crazy hard to keep, even the best of fences will not contain them if they choose to stray. At least, that is always what people have told me, even other Buffalo people. Plus, for such a wild animal, I would want to live on the range where they can roam.
Crazy hard doesn't begin to describe the fencing needed for Bison.
Water buffalo is evidently way different tho. I've seen kids no bigger than a button leadin them down the road all over Asia.
I'm not a goat person, but it's always been my understanding that some goats types will eat brush and weeds--others will not.
Weeds and thistle--2,4-d and Remedy.