I'm on the wrong coast, but in the northeast $100 appears to be the languishing point. There's a very nice 66 I've been watching for over a month sitting at $100.
I've bought two decent treadles this past year. A 1915 15-30 that I paid $50 for. It had been sitting on CL for two months. The lady told me I had doubled the next highest offer. And a 1939 201-2 (still potted) that was mounted in a straight leg treadle that I paid $75 for based on the 201 and not the table.
If he's "Hmmm, I think I might sell this..." then do $100. If he's "I want this thing gone!" my guess would be go lower.