<?php
$i = 0;
$v = 8138; // value : 8138
$bid = round($v / 10); // output : $814
$ftax = $v + $bid;
$stax = round($ftax / 20); // output : tax $448
$pay = $v + $bid + $stax; // 8138 + 814 + 448 = 9400
echo "Value $" . number_format($v) . " bid $" . number_format($bid) . " tax $" . number_format($stax) . " You Pay $" . number_format($pay) . "<br />";
$v = round($v * 1.1);
?>