Speaking as a small business owner it's a helluva cost. Providing healthcare to our employees basically doubles how much we pay them per hour so that they can bitch about how shitty their benefits are. More than that because of the way my union contract is written if my wife and kid have any option for healthcare other than out-of-pocket they are ineligible for my union benefits (which cost me $600 a year and COBRA out at $1800 a month).
That my bennies cost my union $600 a year but me $1800 a month says a lot about the power of collective bargaining. That we've got cartelized multinational healthcare corporations on one side of the table and people whose best options for representation include LegalZoom on the other says a lot about how little "the market" enters into this discussion.