Classifieds theme

I’m trying to make a classifieds site using wordpress after many hours of frustration trying to use OSClass, and OpenClassifieds, only to find that neither of them can do what I want them to do without jumping through hoops or spending money that I simply do not have.

So here I am, wishing and hoping that I’m just bad at searching the web for solutions.
I’ve only just installed WP, so please forgive me if I’m a noob.
I basically want a easy to use classifieds site for my local community to use, and are only able to login with facebook.

So my question: Is there a *free* or very very cheap theme to organize my wordpress site to be an easy to navigate, user friendly classifieds website?

Help is greatly appreciated, thank you in advance.