$re = '/(?:\d+(\d{1,3})*([\,\ ]\d{3})*\.\d+)?.+(sqft)/m';
$str = '"4,882 \\t\\t\\t\\t\\t\\tsqft \\t\\t\\t\\t\\t\\t\\t\\t\\t\\t\\t\\t\\t\\t\\t/ \\t\\t\\t\\t\\t\\t\\t\\t\\t\\t454 \\t\\t\\t\\t\\t\\tsqm"
"4,882 \\t\\t\\t\\t\\t\\tsqft \\t\\t\\t\\t\\t\\t\\t\\t\\t\\t\\t\\t\\t\\t\\t/ \\t\\t\\t\\t\\t\\t\\t\\t\\t\\t454 \\t\\t\\t\\t\\t\\tsqm"';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php