As Dogleg said a big five trip would be out of reach for many of us. If you want to hunt dangerous game buffalo is the only thing over there that could be considered affordable. Even lion hunting can run upwards of $25,000.00 USD just for the cat!
If a guy keeps his ear to the ground, there are cow elephant hunts you hear about from time to time. Hippos would be a lot of fun to hunt on the ground, but a 21 day license isn't very cheap, and with all the game a 21 day license allows, the trophy fees could drive the cost of the hunt to $100K in short order.
Zim is going to be the cheapest place to hunt, and the most dangerous. Mugabee probably won't take kindly to anyone culling his troops. Tanzania is among the most expensive - and the safest.