Please find sample XML code for displaying various options in 'Product Details' page for customizing the product with 'Amount Based Pricing'. i.e. as the user selecting required options, the product price will be changed in runtime by fixed amount that is defined for respective options. 

<?xml version="1.0" encoding="UTF-8"?>
<FORM>
 <PAGES>
    <PAGE title="" id="var" type="HTML">
       <FIELDS>
          <FIELD type="TextBox" label="Person-in-charge (Name):" required="true">
             <PROPERTIES>
                <PROPERTY name="ID">Person</PROPERTY>
                <PROPERTY name="Width">250</PROPERTY>
                <PROPERTY name="cssClass">maintxt</PROPERTY>
             </PROPERTIES>
          </FIELD>
          <FIELD type="RadioButtonList" label="Select Shipping Method" required="true">
             <PROPERTIES>
                <PROPERTY name="ID">rdbRating1</PROPERTY>
                <PROPERTY name="RepeatColumns">3</PROPERTY>
                <PROPERTY name="RepeatDirection">Vertical</PROPERTY>
                <PROPERTY name="RepeatLayout">Table</PROPERTY>
                <PROPERTY name="TextAlign">Right</PROPERTY>
             </PROPERTIES>
             <LISTITEMS>
                <LISTITEM value="Normal">Normal</LISTITEM>
                <LISTITEM price="50" value="Express">Express</LISTITEM>
                <LISTITEM price="100" value="Extreme fast">Extreme fast</LISTITEM>
             </LISTITEMS>
          </FIELD>
          <FIELD type="CheckBoxList" label="How would you rate the quality of our products? ">
             <PROPERTIES>
                <PROPERTY name="ID">CHK3</PROPERTY>
                <PROPERTY name="RepeatColumns">3</PROPERTY>
                <PROPERTY name="RepeatDirection">Vertical</PROPERTY>
                <PROPERTY name="RepeatLayout">Table</PROPERTY>
                <PROPERTY name="TextAlign">Right</PROPERTY>
             </PROPERTIES>
             <LISTITEMS>
                <LISTITEM value="Poor">Poor</LISTITEM>
                <LISTITEM price="5" value="Satisfactory">Satisfactory</LISTITEM>
                <LISTITEM price="5" value="Good">Good</LISTITEM>
                <LISTITEM price="5" value="Very good">Very Good</LISTITEM>
                <LISTITEM price="5" value="Excellent">Excellent</LISTITEM>
             </LISTITEMS>
          </FIELD>
          <FIELD type="ImagePicker" label="Back Details :" required="true">
             <LISTITEMS>
                <LISTITEM>
                   <name>centre_folds</name>
                   <src>http://martjackstorage.blob.core.windows.net/in-resources/a9088bbb-df3e-47c4-839b-75a348f58f8c/Images/userimages/swatches/shirts/Back_Details/centre_folds.jpg</src>
                   <width>100</width>
                   <height>100</height>
                   <price>10</price>
                </LISTITEM>
                <LISTITEM>
                   <name>nopleat</name>
                   <src>http://martjackstorage.blob.core.windows.net/in-resources/a9088bbb-df3e-47c4-839b-75a348f58f8c/Images/userimages/swatches/shirts/Back_Details/nopleat.jpg</src>
                   <width>76</width>
                   <height>87</height>
                   <price>11</price>
                </LISTITEM>
                <LISTITEM>
                   <name>side_folds</name>
                   <src>http://martjackstorage.blob.core.windows.net/in-resources/a9088bbb-df3e-47c4-839b-75a348f58f8c/Images/userimages/swatches/shirts/Back_Details/side_folds.jpg</src>
                   <width>76</width>
                   <height>87</height>
                   <price>12</price>
                </LISTITEM>
             </LISTITEMS>
          </FIELD>
        </FIELDS>
    </PAGE>
 </PAGES>
</FORM>


Note: The 'Amount Based Pricing' is specified as mentioned below in the above XML Code: 

<LISTITEMS>
  <LISTITEM value="Normal">Normal</LISTITEM>
  <LISTITEM price="50" value="Express">Express</LISTITEM>
  <LISTITEM price="100" value="Extreme fast">Extreme fast</LISTITEM>
  </LISTITEMS>