I agree with your view on the copies.  My attitude on that is that by giving the copies at cost, you are working for free, simply volunteering your time and money for another's needs.  You would do better volunteering your time at a hospital, certainly get more out of it.

Of course companies will request that, why shouldn't they?  If someone out there is willing to do it, it is to the company's advantage.  Before I joined the firm that I currently am employed with, I had my own business.  There was a company that I had as a client that paid the fees that I had set for quite some years, and believe me, they had a LOT of copies.  Some days it would take one of my employees entire mornings just to do their copies. 

 At some point, I was told they would no longer pay the fee, but only the cost I incurred.  Obviously I told them to take their business elsewhere (in a rather unpolite manner after realizing I was getting nowhere pleading my case to them) as my employee was costing me money by standing there making their copies, not to mention all the money I needed to advance in order to make the copies in the first place.  Again, your statement to the effect that you are not a bank is aptly put. 

While I certainly do not nickle and dime good clients who request copies and provide many without extra charge, there are clients that do require far above and beyond the norm.  Usually, it is those clients who specify they will only pay the cost and nothing further that are in the way above norm category.  For those inquiries, unless specified by a higher up in our firm, I politely deny doing their business and respond that we cannot handle their request as directed as it is not our policy to provide copies at courthouse fee only.  If that is what they want, I tell them that they can directly request the documents from the courthouse personnel and give them the information to contact the courthouse.  And of course, they will wait longer for it and still pay more money because if courthouse staff makes the documents it costs more than for me to make it personally, even with a service fee added.  :)  Many times I have been contacted again later with the service fee approved.  Go figure.