Changed fighter and monster stats.

I've noticed that there was a big problem with how much a fighter cost in game, compared to their value.

This made some fighters way to good and others a total money pit. 

I want players to experiment with different combinations of fighters, so I've completly changed the cost and stats of the them, this will hopfully make the gameplay more varied and interesting.

Some enemy stats have also been changed, but in a less extreme way.

Please let me know what you guys think of this change.