However, they might still be able to find a less expensive plan in the individual/family market, even paying full price for the premiums. It would almost certainly have a higher deductible and out-of-pocket exposure than the plan Doug's employer offers, but that might be a trade-off that the family considers worthwhile. Doug might find that his employer-sponsored coverage for just himself is very affordable, since employers often pay more towards the employee's premiums than they pay towards additional family members' premiums. So Doug's family might opt to keep Doug on the employer-sponsored plan and get an individual market plan for his wife and kids.
According to a Kaiser Family Foundation analysis, in 2018, the average American worker with employer-sponsored health insurance contributed $1,186 for a single employee health plan and $5,547 for a family health plan. Since this is an average, some employees may be paying much more (employers paid the bulk of the total premiums, which averaged $6,896 for single employees and $19,616 for family coverage).
But it's also worth noting that if they keep the employer-sponsored plan for the whole family, the premiums will almost certainly be payroll deducted on the pre-tax basis. On the other hand, if they opt to buy an individual market plan, the premiums would only be tax deductible to the extent that they (along with other medical expenses) exceed 10 percent of the family's household income, and assuming that the family opts to itemize their tax deductions (increasingly rare now that the Tax Cuts and Jobs Act has greatly increased the standard deduction).