The 577 Tyrannosaur or .577 T-Rex. It's neither cheap or long range but you don't have it listed.
You'll need a rifle stout enough to shoot the T-Rex.
How about a Hannibal rifle made by A-Square chambered in the 577 Tyrannosaur.
Here's a pair of the T-Rex on either side of a 308 Winchester.
The .577 Tyrannosaur was developed by A-Square in 1993 for big game hunting in Africa. The cartridge on the right contains a 0.585-inch (14.9 mm) diameter 750-grain (49 g) Monolithic Solid Projectile which when fired moves at 2,460 ft/s (750 m/s) producing 10,180 foot-pounds (13,800 J) of muzzle energy.