How much is to much? $1 more than you are willing to pay. It will vary from person to person and factor in much more than available money!
- Access to that animal where you already hunt
- Your time
- Your personal hunting goals
- what's important to you: getting animal vs. a "good" hunt with memories
Personally I don't see paying to hunt what I can hunt at home: whitetails. Yes I can pay to hunt a big one or go somewhere with many more deer than NH. If I am going to pay to hunt, it will be something I can't hunt here: elk, mulie, antelope for example.