Skid said..Perhaps the $600 cross trainer is a gym machine of some sort; not cross trainer shoes....

Oh,.. I never thought of that.

Since we're now thinking laterally, I suppose it could also be a $600 personal trainer that you have made cross,

by not paying the $600.

Or by not sticking to the training program ?
Or by not paying another $600 for the cross trainer shoes they were selling?
So many possibilities.
I think we need more information.