H4 to H1 COS amendment process and fee for the same

I am working in US on an H1B. My wife got an offer from an employer and her H1B is approved. They did her H4 to H1 status change based on her old I-94. But she is not in US at the moment. So, the same employer will file for an amendment when she comes back next month.
How much is the USCIS H1B amendment fees? Is it $325 or more, for the same employer, same location, same position, same job description.
Also, can she get her H1 stamped at the moment, and if so, do they still need to amend?
- Thanks in advance