Difference in Health Care Costs per employee

Do any of you out there offer additional compensation to those who have single medical insurance rather than parent/child or family coverage? We have been hit recently with the "You only pay $600 a month for my single insurance coverage, but pay $1800 a month for John family insurance so I should get compensated for that difference."
Comments
Our Finance Director who relocated from Colorado, has expressed his concern that the union will "catch on" to the disparity between single and family coverage, but they haven't said anything yet.
Have had two ee's this year ask if they would drop their company paid health coverage would we in turn pay them this value in additional wages. Our response has been no.
>"You only pay $600 a month for my single
>insurance coverage, but pay $1800 a month for
>John family insurance so I should get
>compensated for that difference."
Yeah, I'll get right on that... just as soon as I cash in all my unused smoke breaks.