Universal Studios and Harry Potter World Days needed

Hi,


How many days are recommended for Universal Studios and Harry Potter World?



There is 3 of us including me the mum and 2x18 year old males.



We will be there in early April 2017.



 Where is the best place to buy tickets from online fromAustralia before we go, or should I buy them there?


Please help.



Thanks!



I didn't find the right solution from the Internet.



References:

www.tripadvisor.in/ShowTopic-g34515-i19-k10314764-Universal_Studios_and_Harry_Potter_World_Days_needed-Orlando_Florida.html

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