COBRA quote is huge, any alternatives? after 4 years as a security officer

The COBRA quote for my family is $300 a month and I do not know how to afford it. I have read a lot of threads here and could not find my exact situation. I saw that marketplace plans might cost less. Is the decision time really that tight?

Thanks for writing this out. I went through something close to it last year, and it settled down once I kept a simple log of every call and form.