I think the bigger questions is "are these cracks showing a faulty foundation, or are they normal?" Settlement cracks are very common in concrete foundations. Concrete cures over a very long period of time and it actually rare not to see even small ones. It is even common in brand new construction. Unless they are quite large(more than a finger's width) they typically do not effect the structural integrity of the home. I might suggest taking some pictures of them and showing them to the inpector who inspected the home to see what his opinion might be. If the seller fills or patches the cracks that could be a sufficient remedy to the situation, again, though, consult the inspector. Additionally, if it is recommended to have a structural engineer look at it, you should know that can be pricey and that's when I would get the attorneys involved. But I think the main issue here is determining if the cracks are anything serious. In my experience it is rare that they are, and when they are, it is obvious that there is a structural integrity issue.