Yes, I mean a bruise on the neck from intense sucking, otherwise
referred to as a love bite.  How did such a thing come to be referred
to as hickey?

I already know that the word hickey means a slight imperfection, I am
looking for a little more in depth, which lang it came from and which
word in that lang will be enough to get my money.

My initial search came up with nothing - dictionaries claim that the
origin is "unknown". It might be a good idea to rethink your pricing
policy, as it is possible that $1.5 would not suffice for a more
thorough research for most researchers.

This seems to me to be a pretty hit or miss thing, somebody who knows
the answer could post and collect my $2.-R

"hickie - 'mark on skin made by biting or sucking during foreplay or
sex,' 1956; earlier "pimple, skin lesion" (c.1915) or 'any unspecified
object' (1909, cf. doohickey, still used in this sense)."

http://www.etymonline.com/h3etym.htm