It's a personal decision. I've made it myself many times hunting small tracts in IL near subdivisions.
If you're not embarrassed that an animal you shot crossed onto property you don't have permission to hunt, you should be. It's just a matter of time before you are talking to an LEO about it.
As for the fine, once an animal crosses the property boundary you have permission to hunt on, you are faced with either wanton waste for not retrieving the animal, or trespass if the landowner chooses to pursue the charges. Trespass connected with hunting can, in many states, cost a hunter his/her hunting privileges.
Making a habit of this or being casual about this is a threat to hunting IMO.