Loosing coverage end of this month. Confused about how to get new coverage

My uncle is loosing his current health insurance at the end of this month. He’s asked about cobra but it’s almost $1000 a month and he can’t afford that. He is currently paying about $250/month of health, dental and vision.

His new job offers health insurance, but only if you work 30+ hours a week. (He works with patients, thus, if patients cancel/reschedule, he doesn’t get hours– since he’s new he is only able to average about 20-23 hours a week at the moment)

Marketplace insurance is about $650/mo minimum, not including dental or vision. He is 56 years old.

What other options does he have, if any, for coverage? He is most worried about major issues, like if he gets cancer or has a heart attack, etc., then he wants to have some type of coverage for that. Are there anything options out there for something like that if he choses not to have regular health insurance but wants something for major issues?

We would appreciate any help or guidance! Online has been very confusing for us! (We spoke with someone who does health insurance and they told us they didn’t know of anything out there other than getting a marketplace plan. I wanted to check here because my sister was able to get help using this sub!)