Given a hash reference, which is what's returned by the curlies with the data inside, you'd read the data with the ->{} construct.

print $hashref->{'itemName'}, $/;
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The business inside the left-side curlies looks like "baseNum", "randomID" and something else stuck together to make a key to a higher-level hash. If so, you'll need to find out its name, but that barely changes how you get the data out. If the bigger hash is referenced by $its_name,

print $its_name->{$the_key}{'itemName'}, $/;
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Some of the data ("allPrices") refers to an array, others seem to be lists presented csv style. You probably need a better spec to decypher all that.