I've been going to MELS for years and I've never heard of anyone purchasing in advance. Their website lists it as first Come first serve. We always arrive a good 30 minutes before the gates open.
I don't believe so, you can call to ask if you aren't shy, it's recommended to arrive at about 7:30 p.m. as it gets crowded quickly due to the small drive into the area. Sorry that I couldn't specifically answer your question.
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