I know someone nearby who's selling one of these for only $30. All I know about it is that it's probably a 1920s model, it's electric, and it has some kind of footswitch with it:
She says it "kind of works". She doesn't seem to know much about it except that if you plug it in it does "something." I'm sure it must be worth at least $30. But on the other hand, I'm not sure what I'd do with it if I bought it. I guess it would be worthwhile just to resell it for a profit on Ebay etc. What say ye?
I think the grey models were introduced in the early 30s. Earlier models were black. Im not really up on the operations of the different models, but Im fairly certain the foot pump indicates this is a secretary model, which was used for playback only, so will have no recorder for recording cylinders. I have my doubts that you'd make a profit on your $30 as not many people are interested in dictating machines. I've got a couple that I picked up cheap, but bought them more as a novelty, and as an accessory for my antiquified office.
If it had the shaving capability, that would be nice as they do a great job of shaving cylinders for home recording but this model doesn't have that ability so as others said, it's basically a great boat anchor.