A US-centric answer because that's what I can help with:

Regardless of the school you go to, look into community colleges and associates degrees. Talk to the schools you're interested in and find out what will or will not transfer in. Some schools are very picky, so don't waste two years on a EE-related associates when they only let you keep your english and history classes. But if they do let you transfer those in, spend a year knocking out those courses at a cheap (maybe even free) community college before going to a university for the engineering program.

$80k is high, but not insane unfortunately in the US. It goes higher. Your best quality-for-cost option is probably going to be Georgia Tech. It's about $6k (plus a bit more for some lab fees and things) per semester, so you're looking at around $48-60k for a 4-5 year program. This is for in-state students. I'm not sure given the current issues in hiring how Atlanta is, but it has had a pretty good job market over the years. Move to Georgia for one year, you'll qualify for in-state tuition. I believe this tuition is also available for green card holders, but I'm not certain.

GT also has (had?) associated programs with other universities in GA, often in lower cost of living areas for similar tuition costs. You'd attend those schools and get a GT engineering degree, some required you to transfer to GT main campus after your second year. I'm not familiar with how these programs currently work or if they still exist but they did a decade ago.

Downside of GT is that they're very picky about transferring in credits for math and science courses. They're less picky about the english and history and other courses that are required. So the community college/associates degree thing only takes you so far there but you can probably knock out 6-8 courses at a community college and transfer them in.

For other state universities, like with GT, you'll want to consider moving to the state for a year or so before attending to establish residence in the state.

For private universities, you can look into them but three things: They're very picky on admittance (because so many people try to get in), their costs are much higher though they offer discounts based on your income/wealth, they're often in higher cost of living areas. Even if you get steeply discounted tuition costs, the cost of living will still give you a high annual cost for attendance.

MS/PhD - Everyone suggesting this is delusional. You cannot start these programs without a bachelors unless you've somehow demonstrated exceptional ability in the field already. From your post, you've done nothing with either mechanical or electrical engineering so these are non-starters for you.

Online - This is an option. However for engineering degrees you'll be missing out on all the hands-on work. If you're an unusually dedicated student (this is more common with older students though), you can get some of this with a home lab but it won't be the same. Get internships and coops to make up for your lack of hands-on experience. Speaking frankly, I would be very disinclined to hire a student with an online engineering degree and no internships or coops in the field (I would hire them into an internship or coop program, though). The lack of hands on experience would suggest they're all theory and no practice, that's not a useful person to hire and would make you less competitive if up against candidates from an in-person program with a decent reputation.