Heck, I GAVE one of those (a 10-10A) away in the Stumpbroke raffle. Looked almost the same, except mine had a 16" hardnose and a new loop of chain on it. I bought it for $25 (running) at a yard sale........then cleaned it up, rebuilt the carb, and replaced a few things (including the chain, which Jeff bought for the raffle giveaway) before sending it on its way to Josh.
I got my SP-81 in trade for doing some work on another saw (Homelite 750 that needed a good strip/CLEANING, a carb rebuild, an intake boot replacement, and some other work). My SP-81 wasn't a runner, but just took some serious cleanup, a carb kit, a fuel line, and a starter rehab to get back in business. My PM700 came to me along with an SXL-925 in trade for a big Husky. It was already a runner. My 7-10A came to me (along with a Homelite Super E-Z auto) in trade for a little Stihl that I refreshed and put a new B/C on. Neither saw was a runner, but they weren't too far from it.
My point is that these 10-series saws are out there. If you're not in a big hurry, even the 82cc saws (which are the most desireable) can be found still for decent money. Ebay's gotten stupid (for both the 70 and 82cc Macs), but that "market pricing" only comes into play if you need to get the thing ASAP. It's not like they're an 895C or BP-1. McCulloch made tons of 'em, and stropped production not too long ago (compared to those "holy grail" Macs)....