this requires customization, as the minimum value works just on the order total. Here is code that can do it, but it will always work this way for manufacturer specific coupons if you select a minimum value.
Version 1.4.1
in www/administrator/components/com_awocoupon/assets/virtuemart/ps_coupon_process.php, around line 571, right after the start of the if statement
<?php
if($coupon_row->function_type2_mode == 'include') {
?>
but before
<?php
// inclusive list of manufacturers
?>
add this
<?php
// verify total is up to the minimum value for the coupon
if (!empty($coupon_row->min_value)) {
$manu_total = 0;
foreach($coupon_row->cart_items as $row) {
if(isset($coupon_row->manufacturerlist[$coupon_row->cart_items_def[$row['product_id']]['manufacturer']]))
$manu_total += $row['qty'] * $row['product_price'];
}
if ($manu_total<$GLOBALS['CURRENCY']->convert( $coupon_row->min_value )) {
return $this->return_false('errMinVal');
}
}
?>
Note this is untested code, so test properly before using in production environment.