With cheap airfare unfortunately you often get what you pay for.
I think for now its all speculations without any solid basis as to what happened.
The plane was fairly new, manufactured / delivered in 2016 and experienced a major in flight catastrophic "Failure" which at the moment
we don't know what type of failure. Explosion in mid air, missile shut down etc etc are mentioned. It does not look like a single part, system
malfunction, failure. No Mayday or any distress call as we know off. (We can rule out MCAS in this case).
The answer could be in the black boxes but for the moment they won't be handed over to Boeing or to any American / Western agencies
who can read them and find the answers, so politics, tensions between Iran and the US will dictate the outcome of this investigation for now.