Sorry, late the party so discussion gone a bit beyond this, but I don't see a great case for socket 1366 beyond personal nostalgia, though I guess minor historical significance since it was start of the Core i line, even though not start of Core. However personal nostalgia is an itch that tends to keep itching until you scratch it. Myself, I have no logical reason to need an AMD 40Mhz 386, but I had one in the day, and I will likely be unable to resist if one crosses my path.
Anyway, I would say that the price for these hasn't really bottomed out yet, and might hit a very low bottom, as natural "age out" bottom would I suspect be in a year or two. However, the Windows 10 support deadline looms and there's gonna be 10+ years worth of stuff made functionally obsolete at one stroke, a massive deluge of newer, objectively better hardware, that will be practically worthless, except to the fraction who are glad to retro or linux re-purpose it. There is still going to massively more "sellers/disposers" than "buyers/adopters" though. In general therefore, the shorter term value of 1366 looks to be around free to negative (pay me to haul it away) BUT, huge but, if you are wanting very specific pieces, you probably want a chance to look for a needle in everyone's sewing supplies, before the deluge happens and you're trying to find a slightly different needle in a tidal wave of needles. So moving earlier might be of benefit, even if you pay a bit more than might theoretically be possible later. However, this may also have the characteristics of a mass extinction event, a pinch point, mass scrappage, so after that occurs, what tickles your fancy from first to fourth gen core might be hard to find... and should a general sense of nostalgia for the period later form, become expensive.
Unicorn herding operations are proceeding, but all the totes of hens teeth and barrels of rocking horse poop give them plenty of hiding spots.