The interpolation in here-documents has no more in common with eval than has normal interpolation in double-quoted strings: my $var = "this is a string with $values";

From perlop:

The terminating string may be either an identifier (a word), or some quoted text. If quoted, the type of quotes you use determines the treatment of the text, just as in regular quoting. An unquoted identifier works like double quotes.

So, if you don't want variables to interpolated:

my $string = <<'EOF';
$50 for shipping
EOF
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