Open the "_RES" file located in the "Huntdat" folder of the game directory on your hard drive. The "_RES" file contains specs for weapons, characters and prices. Changing the values in the "_RES" file will change the values in the game.

the following weapons values can be changed:

power: changing this value to 20 will kill anything with one shot.
rate: the higher the value the faster the weapon will repeat fire.
shots: number of shots or ammo
reload: some weapons have this option and a higher value allows for faster reloading

I didn't see any need to alter the values of the characters but these could be played with as well to control aggresiveness, health and other things listed in the "_RES" file.

Prices for everything can be lowered to a value of 10 and the start value raised to what ever you like, I used 500 so that everything could be purchased right away. One thing I noticed is that purchasing multiple weapons in the selection stage doesn't give you multiple weapons during the hunt.