I would expect that replacing the timing components included disconnecting the battery which would clear stored codes. If these codes are present now, I would expect that they were triggered after the repair.

I once replaced a timing belt and was off by one belt tooth on one cam sprocket. It ran pretty well, but threw codes until I corrected it.

It is possible this is a sensor issue, but if it has two cam shafts and both are throwing a code, I would anticipate it is not just the sensors. It would be odd for them to fail together. Not impossible, though.

If you buy it with this error, the only safe thing is to price it like it is going to need the timing issue fixed. And that is hard to price. It could just be a matter of getting the belt positioned correctly on the cam and crank sprocket. Or it could mean replacing major components. Even if just setting the timing kit correctly, the labor involved can be substantial.