Content Dependencies

Hi! I am prett new to drupal, please help :-)

I need to have a structure of nodes that work like this:

A user posts an offeror a job to do and another user responds with a Quote. Just similar to Myhammer.com...
I already tried with comments to set up a functionality like this, but maybe there is a more elegant way...

Is there a simple way or even better a module that can do this?

THX for any help!