CRM - Implementation Cost?

I've been asked to do a private design/implementation of a CRM for a courier company.

I've done this several times before in my career, but always internally for the company I was employed with.

No idea what to charge. Can peeps sound off with general ranges?

Scope:

Courier company of 20ish employees

Need to review current work processes, select a platform, design and implement.

Assume we're starting from Excel/emails/elbow grease as current "system" so it will be a significant lift at the start.