Misinformation in pure text form has always been cheapest, but is even cheaper now that text generation is basically a solved problem. Photos have been more expensive, it used to take time and skill with a photo editor to produce a believable image of an event that never happened. The cost is now very low, it's mostly about prompting skills. Fake videos were considerably harder, especially coupled with speech. Just a few years ago I could assume any video I saw was either real or a time-consuming, deliberate fake.
We've now entered a time where fake videos of famous people take actual effort to tell apart, and can be produced for a low cost - something accessible to an individual, not a big corporation. We can have an entirely fake video of Trump, or another world leader, giving a speech and it will look like the real thing, with the audiovisual "tells" of it being fake getting harder to notice every few months.
