It has been all over the news, the way the New York state courts have been applying the Ignition Interlock Device has been ruled unconstitutional since August 2010.
It rolled out the devices on first time offenders too fast and thus haphazardly infringed their rights under due process, equal protection, and overall fairness.
Whether that idea has any applicability to the interlock law you mention, we simply cannot tell online.
Kansas's statute has more procedural safegaurds than the New York law seems to have. It is not applied so haphazardly, nor on every vehicle. However the argument that the cost varies is interesting as well as the point that there is no exception for those unable to pay. This is important as an interlock can be required before reissuing a license, even if you do not own a car. I am not aware of Kansas litigation to this point which has rasied the issue.