Blue and White Plate (Kangxi?)

[williamh]

It looks like a Kangxi Plate. It has some cracks and rust. Can it date from the 17th Century or is it a modern replica?
Sorry for the  quality of the last photo.

[williamh]

Another photo of the bottom. How much does a repaired crack like this affect the value of a plate?

[peterp]

A picture showing the foot rim shape, taken at an angle, may help.

I have heard that some restored items have a value of only 25-35%, but that is also dependent on rarity and type of item, of course.