This is common area to have wear and damage. It is a shame because it makes sitting on the seat uncomfortable and is only going to get bigger till it is fixed properly.
The top is leather and the sides are vinyl, which is typical. If we replace the piece, we usually suggest a vinyl replacement as it is cheaper and unnoticeable.
In this case, the leather could be restored and money can be saved.
A Win-Win situation.
When we price this, we almost always include a thorough cleaning of the seat and a fresh dye coat to keep everything uniform.
This job was done in the parking lot, so it was convenient for everyone.