For some reason I can't reply to a child of this comment. It would be easy enough to require all advertising to publish the lowest and highest all in price with

For some reason I can't reply to a child of this comment. It would be easy enough to require all advertising to publish the lowest and highest all in price within the geographic area of the advertisement. For many ads, it would also be possible to require at least per state granularity. That would not be an onerous burden.