right now i am using a module from github, that creates a page in product that lists all the "prices" from product.pricelist of the product. What i want, is to take the "price_list" of the product, and substract the discount in each line.

import math
import re
import logging
import openerp.addons.decimal_precision as dp
#from _common import rounding
from openerp import tools
from openerp.osv import osv, fields
from openerp.tools.translate import _
_logger = logging.getLogger(__name__) # Need for message in console.
class product_template(osv.osv):
    _name = 'product.template'
    _inherit = 'product.template'
    _columns = {
        # For display price in product.
        'prices_ids': fields.one2many('product.pricelist.item', 'product_id', 'Supplier'),
        'price_bas': fields.Char('Display Name', related='price_list.price.bas',store=True),
       }
product_template()
class product_pricelist_item(osv.osv):
    _name = 'product.pricelist.item'
    _inherit = 'product.pricelist.item'
    _columns = {
        
        }
product_pricelist_item()

Bold, added by me, making some mistakes. I couldnt get to the point of showing the "price_list" = standard price of the product, into the new price page, yet.

This is the xml.

<?xml version="1.0" encoding="utf-8"?>
<openerp>
<data>
    <record id="price_list_tab_view" model="ir.ui.view">
        <field name="name">product.template.product.form</field>
        <field name="model">product.template</field>
        <field name="type">form</field>
        <field name="inherit_id" ref="product.product_template_form_view" />
        <field name="arch" type="xml">
            <xpath expr="/form/sheet/notebook" position="inside" version="7.0">
                <page string="Prices" >
                    <group >
                            <field name="price.bas"/>
                    </group>
                    <group colspan="2" col="2">
                        <field name="prices_ids" nolabel="1"  widget="one2many_list" >
                             <tree string="Price List">
                                 <field name="price_version_id"/>
                                 <field name="min_quantity"/>
                                 <field name="price_surcharge" string="Descuento"/>
                             </tree>
                         </field>
                    </group>
                </page>
            </xpath>
        </field>
    </record>
   <!-- it for posible add price from product -->
    <record id="price_versionid_form_view" model="ir.ui.view">
        <field name="name">product.pricelist.item.form</field>
        <field name="model">product.pricelist.item</field>
        <field name="type">form</field>
        <field name="inherit_id" ref="product.product_pricelist_item_form_view" />
        <field name="arch" type="xml">
            <xpath expr="//field[@name='product_id']" position='before'>
                <group col="4" string="Price version">
                    <field name="price_version_id"/>
                </group>
            </xpath>
        </field>
    </record>
</data>
</openerp>