price_security/views/product_view.xml

<?xml version="1.0"?>
<openerp>
    <data>
    <!-- add can modify pries -->
        <record id="product_template_only_form_view" model="ir.ui.view">
            <field name="name">price_security.product.form</field>
            <field name="model">product.template</field>
            <field name="inherit_id" ref="product.product_template_only_form_view"/>
            <field name="arch" type="xml">
                <xpath expr="//page[@string='Information']/group/group" position="inside">
                    <field name="can_modify_prices"/>
                </xpath>
            </field>
        </record>

        <record id="product_normal_form_view" model="ir.ui.view">
            <field name="name">price_security.product.form</field>
            <field name="model">product.product</field>
            <field name="inherit_id" ref="product.product_normal_form_view"/>
            <field name="arch" type="xml">
                <xpath expr="//page[@string='Information']/group/group" position="inside">
                    <field name="can_modify_prices"/>
                </xpath>
            </field>
        </record>

    <!-- make readonly for group_restrict_prices -->
        <record id="product_readonly_template_only_form_view" model="ir.ui.view">
            <field name="name">price_security.product.form</field>
            <field name="model">product.template</field>
            <field name="inherit_id" ref="product_template_only_form_view"/>
            <field name="groups_id" eval="[(6, 0, [ref('group_restrict_prices')])]"/>
            <field name="arch" type="xml">
                <field name="list_price" position="attributes">
                    <attribute name="readonly">1</attribute>
                </field>
                <field name="can_modify_prices" position="attributes">
                    <attribute name="readonly">1</attribute>
                </field>
            </field>
        </record>

        <record id="product_readonly_normal_form_view" model="ir.ui.view">
            <field name="name">price_security.product.form</field>
            <field name="model">product.product</field>
            <field name="inherit_id" ref="product_normal_form_view"/>
            <field name="groups_id" eval="[(6, 0, [ref('group_restrict_prices')])]"/>
            <field name="arch" type="xml">
                <field name="lst_price" position="attributes">
                    <attribute name="readonly">1</attribute>
                </field>
                <field name="can_modify_prices" position="attributes">
                    <attribute name="readonly">1</attribute>
                </field>
            </field>
        </record>

        <record id="product_pricelist_form_view" model="ir.ui.view">
            <field name="name">product.pricelist.form</field>
            <field name="model">product.pricelist</field>
            <field name="inherit_id" ref="product.product_pricelist_view"/>
            <field name="arch" type="xml">
                <field name="active" position="after">
                    <field name="sequence"/>
                </field>
            </field>
        </record>


        <record id="product_pricelist_view_tree" model="ir.ui.view">
            <field name="name">product.pricelist.tree</field>
            <field name="model">product.pricelist</field>
            <field name="inherit_id" ref="product.product_pricelist_view_tree"/>
            <field name="arch" type="xml">
                <field name="name" position="before">
                    <field name="sequence" widget="handle"/>
                </field>
            </field>
        </record>
    </data>
</openerp>