We stayed in Grand Case the last week in February and visited shops and restaurants there every night. While there were people around every night, Tuesday night was packed, and all the restaurants and shops were very busy, as well as the street stands. it was a noticeable boon for the restaurants, including the high end ones, compared to the other nights. I'm guessing the costs for the event includes things like the extra guards to block off the street and direct traffic, for example, plus the other bands playing along the street are probably paid.
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