The entrance to the store from in the park is by Wax Works
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The building on the top is where the Legacy Store is and the one on the bottom is Wax Works
Im guessing the reason why they have it set it up to be only entered from within the park when Scary Farm starts at 7 is likely to avoid people attempting to enter the event from the store on the Marketplace side
The store closes to normal guests at 4:30 on the Marketplace side and reopens to Haunt Guests at 7 and appears to close 2 hours prior to the end of the night (11pm for 1am nights and Midnight for 2am nights). This chart below can be found in the Knotts website
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