well you seem to know alot about the domains and their potential, but not knowing if they made a $100, $1,000 or $5,000 offer who knows if you're lucky or not.
they are short and brandable, personally i'd develope as they seem to be on an upswing with decent overture results 2,200 for 'xxxx ups' would be pretty easy to have an mp3 type site built with alot of advertising possibilities.
good luck either way