1. An image processing apparatus comprising: a memory configured to store incorporated charging information that is set for a function executed by an image processing section; and at least one processor configured to implement: the image processing section that processes an image; a plug-in adding section that adds a plug-in, the plug-in being a function executed in corporation with the image processing section; an additional-charging-information adding section that adds additional charging information as the plug-in is added by the plug-in adding section, the additional charging information being set for a job included in the plug-in; a charging section that charges for a job on a basis of the additional charging information, in a case where the job to be executed is included in at least one job included in the additional charging information and the job to be executed is executed; and a job search section that searches whether or not a job to be executed exists in the incorporated charging information, in a case where the job is not included in the at least one job included in the additional charging information, wherein the charging section charges for a job on a basis of the incorporated charging information, in a case where the job to be executed is determined to exist in the incorporated charging information by the job search section.