Replace dot with comma, and comma with dot PHP

Question

i have a price column in a table. price is Turkish lira like that. 1.200,50. i want to make +%10 to price. but give me 1.32 not 1.320,55

here is my code

<?php
$num = "1.200,50";
$newnum=$num*10/100+$num;
$formattedNum = number_format($newnum, 2);
echo $formattedNum;
?>