I know nothing about these sights, but given their ever growing popularity it seems like it might be good to have one for a collapse of society situation. Can anyone tell me what is lowest priced thermal night sight currently available that has a somewhat decent quality? Can you use these sights at all during the day time, i.e., for sighting them in. Where I live you could shoot for hours during the day time without attracting attention whereas shooting at night would result in a police visit.