What provider does your employer use, and did your employer specify how much they were covering?
For my health insurance through work (Independent Health), it works out to about $65/month, and dental (Guardian) is about $15/month, and that is my pretax out of paycheck expense. Work pays more than half of the cost, so even if I were to receive the same reduced ‘per person’ rate from these providers, it would be costing me over $200 a month for health and dental.
I haven’t personally shopped for insurance outside of an employers plan, but most people whom I’ve talked to who didn’t get insurance through work (either for a lack of it being offered or any other reason) did not end up purchasing insurance on their own due to the cost.