Depends on the state and plan. For me COBRA was $2000/mo. When employed I paid like $20/mo and my employer paid $1980/mo. When I left I paid the entire amount.
The plan you had was $2,000 (wow, that's really a lot though) and your employer was willing to pay $1,980 (again, that's a lot compared to employers I worked for) in addition to your salary.