Ebay prices are set by the buyers not the sellers, although there are "offerers", not sellers who put non-viable starting or buy it now prices on their stuff, and it doesn't sell. If you search only the sold items, you can get a good grasp of what selling prices are, not the wishful thinking. Most of the wishful thinking has been set by the sales of a few desirable sets, then sellers price their common stuff at the same price because they can't see how theirs is different.
I like P&C and had a lot of it in my early mixed tool sets that I used. Eventually I replaced all the mismatch with matched sets of stuff, and it became surplus and just more clutter. I never had enough to put together very good sets of P&C, and the much more common Proto became the basis of what I keep and use.
P&C aren't particularly good sellers. I put my sets out on ebay last year, and they sold, but for very low prices. I put all the miscellaneous stuff I had out for sale a while back for $1.50 per item overall price for the lot, and had no takers, so they went into my discard pile. The same stuff in Craftsman would have brought double that and would sell easily on ebay. I've been selling my accumulation of old tools for a couple of years now, and I see very little demand for most old SAE tools. There is specific demand for some of the harder to find pieces to fill out sets, but the run of the mill stuff that isn't in sets won't even pay for the postage on it.
My experience has been that Craftsman sells. Proto, Williams, Snap-on, Mac, SK, some Plomb, some Indestro, some Bonney sell. Bog, Herbrand, Pennens, P&C, New Britain, Mustang, Giller, Thorsen, Husky, Wizard, Powr-Kraft, Action, Walden, Blackhawk, Riverside, etc you might as well discard. Or just put it in large lots filling a flat rate box along with the taiwan and chinese tools and hope that you can get a few dollars plus the flat rate box shipping for it. I sold probably 500 pounds of old tools that way just before I moved last year. A 25 pound medium flat rate box typically brought about $15 plus postage. Mostly I've just given up on even doing that, and just discard them now. Listing, packing, and shipping 500 pounds of tools to get $300, and paying ebay and paypal fees on that just isn't a worthwhile endeavor. Add in a couple of ebay douches that file a not as described claim to get you to give them the tools for free, and it really makes it a non-winner.
I had a lot of tools up on ebay a few weeks ago, and no bidders on 3 successively lower starting prices. I tossed them, and then had an amusing message from someone telling me that they had been watching them and wanted to know if I was going to list them again with a lower price. When I said no, they were discarded, he wrote back that was horrible, because he really wanted and needed them for his collection! I think my last price was down to me getting $3 out of the lot, after postage and ebay/paypal fees. My mode of operation is to list 3 times, and no sale they're discard. With the wide exposure that ebay has, if you don't sell in 3 tries, there's no demand. I do try to sort out the stuff by maker and put it on ebay, as a service to collectors. I'd like to at least make it available; I use ebay as a source for stuff I'm looking for and am grateful that sellers take the time to make it available. But, if it doesn't sell, out it goes.
I think there will be a golden age of tool collecting in about 15 or 20 years, when most of the old stuff has been tossed out. Then, there will be enough competition for the remaining pieces to make them worthwhile for people to catalog and sell them, and they will become more available, although higher priced. As with most collectibles, the value comes when 90% of them have been trashed and the remaining supply becomes sought after. I think the work that Twertsy and Alloy Artifacts has been doing on cataloging information on the tools is the first signs of this happening. Their work will be some of the basis of determining what is rare and sought after, and what is common.