In short
Cairo is not visited, it is crossed. The Grand Egyptian Museum, Giza, Khan el-Khalili and the citadel each want half a day.
Zamalek and Maadi hold the housing foreigners settle into: quieter, greener, dearer.
What it really costs
The exchange rate matters enormously: the Egyptian pound has lost a great deal of value, which makes the city very affordable in euros.
Entry tickets to the archaeological sites are the exception: they rise every year and are paid in foreign currency.
What nobody tells you
The traffic and the pollution are wearing. Many visitors fall ill in the first week, without the food being to blame.
The pyramids are in the city, not in the desert. Getting the photograph without buildings takes precise framing, and that is normal.