Retesting on the snap isn't the critical part now, you had a positive AND you had bloodwork abnormalities. Tests like Snap may only show positive if the immune system is competent enough to mount an antibody reponse. So the negative nap does not mean not infected. We have also seen a number of dogs test negative on the snap, but positive when titers are run. Maybe though, it does mean acute infection that is getting under control, which would be good!
Did you recheck blood counts and platelet, or is that later?
Jealous about your vet prices - everything here is getting very expensive!