"cannot afford for" is correct and usable in written English.
You could use it when you are describing something you cannot pay for or buy. For example: "I cannot afford for a new car right now."
Malawi cannot afford for that to keep happening.
Frankly, the world cannot afford for them to fail.
Still, Mr. Bates and other Microsoft executives cannot afford for Skype to be too independent.
Democracy cannot afford for the gap between prodigies and the rest to grow wider.
Patients cannot afford for the government to ignore expert warnings," Abbott added.
Taxpayers cannot afford for the state to leave hundreds of millions of dollars on the table.
We cannot afford for the non-EU student debate to go on any longer.
They cannot afford for this country to fall off a cliff.
Our children cannot afford for us to sit idly by in the face of these facts.
Nurses cannot afford for this to continue, and neither can the health service".
Public services cannot allow this to happen, and we cannot afford for this to happen.
