Only info I easily found on that model number.
http://www.searspartsdirect.com/par...ts/Welder-Parts/Model-113202460/0247/0753000?pathTaken=&prst=0&shdMod=113202460
I still think it's worth $40. I doubt for that machine you'd need a stinger and clamp worth $40. A quick look at HF shows a plain steel spring ground clamp similar to what was originally on that machine for about $8. Stinger would set you back about $10 from what I see. I bet I could find nicer ones at about the same price if I hunted a bit more. Cable you are probably close on the lower end if you hunt some. used you might save a few bucks if you looked hard enough.
Still even if it's $100-120 when all is said and done, it's a lot better than $250 or so for a new Lincoln Ac machine for someone just starting out on a buget, It's a lot more machine than a small Harbor freight 110v stick machines in thae same price range. A lot also depends on your area. I've seen people asking crazy kinds on money posted up here on CL adds well above retail for AC machines.
If he gets 2-4 years of use out of it and keeps it in nice shape, selling it for $75-120 wouldn't be unreasonable. At that price he'd get back almost 100% of his investment at best, and only have spent maybe $25-50 overall at worst for the use of the machine over those couple of years. Not a bad investment. A lot better than buying a new AC 225 and selling it for maybe $50 more and loosing $100-150 over the original price.
the lack of leads also gives him some room to bargain, though at that price admitedly not a lot. If the person doesn't know much about welders, chances are the leads may even be there, or you can haggle them down a few bucks simply using the reasoning you have to dump more cash into the unit to get it functional and can't test it as is. If the seller is simply trying to unload grandpas old junk, they'd probably take $20 for it just to get it out of the shop.