This is a tough one, I work in a fairly big govn office, we have auto machines on each floor (Delonghi Magnifica), they are domestic, and really not suitable for the work load they get. (50-100 a day). The poor things constantly have "descale" flashing on their displays. No one maintains them and the beans that work supplies for the machines are terrible.
I bought a new grinder for home, so I took my old grinder (sunbeam EM0480) to work. I take my own beans and grind on-demand at work, dosing the auto machines through the pre-ground chute.
The milk attachment on all the machines is busted, so I have to nuke a cup of milk if I want a milk drink, then brew my pre-ground in to the nuked milk. Its really not that pleasant.
I also grind up for a few blokes at work, and hit em up for 50c per grind. It covers the cost of the beans.
As the machines are constantly breaking down, Ive seriously considered buying a cheapish machine for work, perhaps a sunbeam EM6910 or similar. The problem is, as you mentioned, it will be abused, left filthy, and operated by people that have no clue what they are doing. As it is, I keep my grinder in a cupboard, or at my desk so no one uses it.
I thought about taking in a machine and putting a sign on it. Something that says people are welcome to use it as long as they know what they are doing and keep it clean. But still, I dunno.
At times when the machine is broken, or there are too many people surrounding it, I bust out my clever coffee dripper, and grind a suitable roast for that instead, let it brew at my desk and enjoy, although I must admit, I drink milk coffees (or espresso) more than black.
I would never put an E61 machine at work, it will get thrashed, abused, destroyed. Or perhaps the others at work are smart enough to not touch something they dont know about... *ponder*... nah. good luck