So, here’s the thing:
Almost every aspect of the Iron Man suit (from its exoskeleton, jetpacks, VR display, weaponry, and neuro-link) is possible to build today, and altogether cost a few dozen million dollars. For most big-name companies, that’s very affordable, and it’s even why some Iron Man suits exist today.
However, there is one part of the suit that is impossible to re-create: the arc reactor.
The arc reactor is a portable energy source the size of a hockey puck, powering the equivalent of around eight nuclear power plants. There is just no technology in our time to even come close to that.
If such a power source were to be developed today, it would likely turn those millions of dollars of a suit expense into tens of billions just for the power source alone.