churchill's price

still looking for vol. 3 and 4 of churchill's history of the english-speaing peoples.
thank you ed for those 2 links to rare book dealers!
they want between 450 and 3,000 pounds. höhö.
the 2 volumes i have i bought in oxfam, an impulse buy for something like 5 quid. an outrageous price for a charity shop!
so my question is: who would give 2 out of 4 volumes away, or who was clever enough to buy an incomplete set of only 2 before me, when they could have had them all?
strange...