Howdy,
Your post caught my eye. I'm new on here, so take my advice with a grain of salt. I'm a bit non-mainstream SB since I have a Model A 9 jr that I really like, but I live near Pittsburgh (I assume you do, too, since you mentioned Mario), and I watch SB sales, looking for parts mostly. Sometimes I may buy a clapped out 9N lathe just to get something off it, and then sell the rest, so I can tell you an idea of prices around here.
A 9A with a small amount of tooling just sold down in the panhandle of WV this weekend for $525. It lasted on CL about an hour, I reckon. A decent looking 9C has been sitting in Ohio for months below $500. When you get around Akron or Buffalo, SBs are everywhere, it seems, and that keeps the price low. As you get down toward Frederick, MD, you start to see prices go up. Near DC, I see 9As listed well above $2000. I don't know if they sell or not.
But, I'd estimate an average 9A with some wear, a 3 jaw chuck, a lantern post, and a dead center, and nothing much else to be worth around $650 in Pittsburgh. Anything extra, inluding way condition, adds on. If you list, try listing east of here; I'd think nothing of driving 200 miles to get a taper attachment for mine, and I think a lot of folks are just like that.