[overgryphon]

An employee that leaves after a year has decided that they do not want to work for you. This employee is sacrificing a year's worth of work mastering your processes, environment, and code base in order to go start over somewhere else where they need to learn a new code base.

A couple thousand dollars isn't enough to convince most people to start over- something about their current work place made leaving seem attractive. Either the job does not fit them well or have reasonable paths for advancement (both from a development and career perspective), you are underpaying the employee, the work/social environment is bad, or something significant in their personal life has changed (graduating college, spouse got a job somewhere else, ect).

Poaching isn't unfair. You never have any guarentee for how long an employee will work for you, just as your employees have no guarentee they will still have their job tomorrow. The problem in the above situation isn't poaching; the problem is the employee wanted to leave.