I don't know what you think "close-to-new" value means. That can mean the retail price for a new lens, or it can mean the increase in cost of a body/lens bundle over just a body.
KEH sells the 18-55 new for $200, EX+ for $100. I'd say $100 is your max. $50 might be a reasonable expectation.
Amazon is currently selling the 4Ti for $60 cheaper with the 18-55! So go out and pay someone to take that baby off you hands!
There are two variants of the 75-300 III, one has USM. Which do you have? KEH has the USM version new for $200, the USM at EX for 100, the non-USM also at EX for 76.
Craigslist is my usual first thought on a lens sale, especially lower end. Someone here is, optimistically, I think, selling the 75-300 III non-USM "brand new" for $150. Two people, actually.