Group insurance, on average, is twice the cost of individual plans, not the other way around. It may seem as though group insurance cost less, but often the enrollee does not take into account the employers contribution to the total premium. Group insurance is guaranteed issue in most cases, meaning they can't exclude an applicant, no matter their condition. Someone has to pay for this. There are many others reasons why group is more expensive, such as maternity, COBRA, Portability, etc., and all the other state and federal mandates.
Individual plans may exclude certain conditions, or refuse coverage. The upside is that if you are generally healthy, they are your best bet, especially with the higher deductibles. You can pick the plan best for you, and not what the group is offered.