Negative discount group on some custommers

[mc12345678]

Hello, Im working on a membership design for my site, I made one simple change that works pretty fine:
I modified functions_prices.php around line 26

    if ($specials->RecordCount() > 0) {
//      if ($product->fields['products_priced_by_attribute'] == 1) {
        $special_price = ($specials->fields['specials_new_products_price']); 

to

    if ($specials->RecordCount() > 0) {
//      if ($product->fields['products_priced_by_attribute'] == 1) {
        if ($_SESSION['customer_id']) {$special_price = $specials->fields['specials_new_products_price'];}
        else {$special_price = (($specials->fields['specials_new_products_price'])*1.05);} 

that way all custommers that have registration and are logged in can see prices normal and the customers that are not logged will see the prices +5%, also that makes the changes in the cart and on shipping total.

The problem is here: I want to have an profile (lets name it - orders by phone) from wich I can make order with 5% above the regular price that registed user pay, because this 5% are the income that goes for phone and employe expenses.

Is there a way to create an group discount -5% (not +5%!) so I can assign it to that profile "orders by phone"?

I assume that I have to give

$_SESSION['customer_id'] = id (of that profile) 

but I cant find the right way to do it.

Thank you

Understand that in part asking for custom code. That said, if you have say a single "order by phone" profile which has its own limits when providing information to call in customers, then something like the below would charge the same 5 percent that is seen by a non-registered/not logged in customer. Additionally, I've added some additional "sanitization" checks to your code:

    if ($specials->RecordCount() > 0) {
//      if ($product->fields['products_priced_by_attribute'] == 1) {
		if (isset($_SESSION['customer_id']) && is_numeric($_SESSION['customer_id']) && zen_not_null($_SESSION['customer_id']) && (int)$_SESSION['customer_id'] == $_SESSION['customer_id'] && $_SESSION['customer_id'] == X) {$special_price = $specials->fields['specials_new_products_price'] * 1.05;}
		elseif (isset($_SESSION['customer_id']) && is_numeric($_SESSION['customer_id']) && zen_not_null($_SESSION['customer_id']) && (int)$_SESSION['customer_id'] == $_SESSION['customer_id'] && $_SESSION['customer_id']) {$special_price = $specials->fields['specials_new_products_price'];}
		else {$special_price = (($specials->fields['specials_new_products_price'])*1.05);}

Now, if your user is in fact part of a group, then need extra code to identify whether the user is in the desired group(ing). That would be an additional check at the end of the first if test and entered similar as provided. It would replace the session test against X.

BTW, X is the number for the customers_id that represents your phone order user.