Drives are really cheap now. Last week I got a 500g seagate for $175. It's great because at that price you bill the client for the drive, which is negligible, get the whole thing off your system, which is creatively cathartic, and when they show up the next week wanting a change because the janitor in their german bureau wants you to trim 2 frames off of a shot, bam, it's a grand to reload the whole thing and make that change. Because there's actual physical coordinating involved (sending drives back, etc), clients tend to have more realistic expectations for additional charges, at least in my experience. In other words, they feel more comfortable trying to get a free 'hey i know it's an easy tweak so can you do me a free favor' edit when they know you have it loaded in the system. When they have to ship the drives/data, they recognize the logistics and pay accordingly.
This is more in relation to agencies and smaller corporate clients. With larger clients you tend to have to cater to what they want. The upside is bigger pays much better so as to avoid the whole nickel/dime thing.