Price shows the "Moving Spotlight" model of time tries to be both inclusive (accounts for all times) and exclusive (now is uniquely existent) but can't. From this he concludes there is no unique now (i.e. presentism is wrong). I would suggest two softer possibilities are
1. the Moving Spotlight model is wrong
2. it doesn't take into account the possibility that there could be two different kinds of ontology at play (for example ontology1, where the objects all exist, and ontology2, where which properties "exist" is a function of the object: the former is inclusive and the latter exclusive, I think...).