Hi Bob,
Your solution here is great, I found it very helpful. I have however run into a problem I'm hoping you can help me to resolve.  I have a visualforce page that we use for product selection on our opportunities. I've updated it recently with a couple of Jquery functions (based on your response herein) that allow users to edit the sales price and auto-calculate the discount and vice versa. It works great if there is only one product added, but once I add more than a single product the calculations go wonky -- I assume because the code does not know which row to update.
One Product

Two Products


How can I ensure that my jquery is only updating field values in the row I'm editing?

Relevant Code

<script type='text/javascript'>

        function calculateDiscount(){
            var discount= 100*($('[id$=dp]').text() - $('[id$=sp]').val())/$('[id$=dp]').text();
            var discountRounded = discount.toFixed(1);
            $('[id$=disc]').val(discountRounded);
        }        

        function calculateSalesPrice(){
            var salesPrice= $('[id$=dp]').text() - ($('[id$=dp]').text() * $('[id$=disc]').val())/100;
            var salesPriceRounded = salesPrice.toFixed(2);
            $('[id$=sp]').val(salesPriceRounded);
        }             
</script>


<apex:form >
        <apex:pageBlock title="Selected {!$ObjectType.Product2.LabelPlural}" id="selected">

            <apex:pageblockTable value="{!shoppingCart}" var="s">

                <apex:column >
                    <apex:commandLink value="Remove" action="{!removeFromShoppingCart}" reRender="selected,searchResults" immediate="true">

                        <apex:param value="{!s.PriceBookEntryId}" assignTo="{!toUnselect}" name="toUnselect"/>
                    </apex:commandLink>
                </apex:column>

                <!--********** Product Name **********-->
                <apex:column headerValue="{!$ObjectType.Product2.LabelPlural}" value="{!s.PriceBookEntry.Product2.Name}"/>

                <!--********** Product SKU **********-->
                <apex:column headerValue="{!$ObjectType.OpportunityLineItem.Fields.SKU__c.Label}" value="{!s.PriceBookEntry.Product2.SKU__c}"/> 

                <!--********** Annual Product Term **********-->
                <apex:column headerValue="Annual Term" id="pt" rendered="false" value="{!s.PriceBookEntry.Product2.Product_Term_Years__c}"/>                         

                <!--********** Quantity **********-->
                <apex:column headerValue="{!$ObjectType.OpportunityLineItem.Fields.Quantity.Label}">
                    <apex:inputField value="{!s.Quantity}" id="quant" style="width:70px" required="true">
                        <apex:actionSupport event="onchange" reRender="tot"/>
                    </apex:inputField>
                </apex:column>

                <!--********** Service Term in Months **********-->
                <apex:column headerValue="{!$ObjectType.OpportunityLineItem.Fields.Service_Term_in_Months__c.Label}">
                    <apex:inputField value="{!s.Service_Term_in_Months__c}" id="svc" style="width:70px" required="true">
                        <apex:actionSupport event="onchange" reRender="tot"/>
                    </apex:inputField>
                </apex:column>                                        

                <!--********** Discount (Manual) **********-->
                <apex:column headerValue="{!$ObjectType.OpportunityLineItem.Fields.Discount_off_list_manual__c.Label}">
                    <apex:inputField value="{!s.Discount_off_list_manual__c}" id="disc" style="width:70px" required="True" onkeyup="calculateSalesPrice();">
                        <apex:actionSupport event="onkeyup" reRender="spproxy"/> 

                         <!--<apex:actionSupport event="onkeyup" action="{!calculateSalesPrice}"/>-->
                    </apex:inputField>                                            
                </apex:column>                    

                <!--********** Sales Price **********-->
                <apex:column headerValue="{!$ObjectType.OpportunityLineItem.Fields.UnitPrice.Label}">
                    <apex:inputField value="{!s.UnitPrice}" id="sp" style="width:70px" required="true" onkeyup="calculateDiscount();">
                        <apex:actionSupport event="onchange" reRender="tot"/>
                    </apex:inputField>                                          
                </apex:column>

                <!--********** Disti Transfer Price (Standard) Hidden **********-->
                <apex:column headerValue="{!$ObjectType.OpportunityLineItem.Fields.Disti_Transfer_Price__c.Label}" rendered="True">
                    <apex:outputText id="dp" value="{!s.PriceBookEntry.Disti_Transfer_Price__c}"/>
                </apex:column>

                <!--********** List Price (Standard) Hidden **********-->
                <apex:column headerValue="{!$ObjectType.OpportunityLineItem.Fields.ListPrice.Label}" id="lp" value="{!s.PriceBookEntry.UnitPrice}" rendered="True"/>

                <!--********** Total Price (display only field) **********-->
                <apex:column headerValue="Total Price">
                    <apex:outputText id="tot" value="${0, number, ###,###,###,##0.00}">
                        <apex:param value="{!IF(s.PriceBookEntry.Product2.Product_Term_Years__c != null,(s.Quantity * s.Service_Term_in_Months__c * s.UnitPrice)/(s.PriceBookEntry.Product2.Product_Term_Years__c*12),(s.Quantity * s.UnitPrice)) }"/>
                    </apex:outputText> 
                </apex:column>                                   

            </apex:pageblockTable>


            <apex:pageBlockButtons >
                <apex:commandButton action="{!onSave}" value="Save"/>
                <apex:commandButton action="{!onCancel}" value="Cancel" immediate="true"/>
            </apex:pageBlockButtons>

        </apex:pageBlock>