Nope, I wouldn't get replacement pump from a junk yard (if at all possible).
Try Rock Auto, Summit Racing, or even eb*y. Ya, I know, eb*y!?..., but I bought a brand-new replacement distributor for my 2000 Chev truck for less than $75 (Chev wanted ~ 300, while RA and SR wanted about 150-250 depending on the brand). Just look for a lot of positive reviews on the seller tho.