And I think 5 sales per year is too generous. In our old town there was a limit of 2 per year with a permit. I've forgotten how much the permit was, something like $5 and not unreasonable. They probably only check nuisance sales for permits though. In different areas we would see the same sales up almost every weekend and you just feel bad for the neighbors who live with that eyesore and traffic issues all the time. These were sales that would just get covered with tarps and left on the lawn all the time.
Someone at the end of the article complained that garage sales are a good way to recycle items and they're afraid that they'd just get thrown away otherwise. Anyone who would go to the trouble of hauling their stuff out, sorting it, pricing it and setting it all up on tables, then sitting out for days watching it isn't going to balk at the drive to the secondhand store. More likely, they'll just hang on to it until the next sale is allowed.