Dynamically Adjusting Price Field on Product

Hi,

I am currently developing a paypal / gravity forms solution. Right now I'm experiencing a strange validation error. Basically, when I change the price on a product and the form validates it tells me that the price fields needs a correct value. However this only occurs when the price is DIFFERENT than the value upon the initial page load.

That being said, I believe that the form is validating against the original price.

Confirming my belief, when the form reloads and lets me know that the price needs a correct value, I can submit the form and it works as intended.

Any insight on how I can overcome this problem??

Any and all help is appreciated!

http://development.cftacs.org/registration-forms/?fid=31&firstName=Chris&lastName=Carvache&courseTitle=Robbery%20Preparedness&courseNumber=Spring11Web115Web21010%2F20%2F2011&email=chris@northeastwebdesign.com&coursePrice=255.0000&delivery=Webinar&deliveryType=Live+Webinar&courseDate=October+20th%2C+2011&courseTime=11:00%20AM

Sorry for the long link!

Okay that makes sense... Basically I am using some jQuery calls to update the price. See below

/********************************************
 * BEGIN: Webinar Logic **********************
 ********************************************/
	// Hold the original price
	$webinarOriginalPrice = $('#input_31_6').val();

	function webinarChangeEvent(){
		// Test to see if the name field is blank or not
		$theString = ($('#input_31_30').val()) ? $('#input_31_30').val() : '';
		$.trim($theString);
		parseFloat($theString);
		if ($theString.length > 0) {
			// Change the PRICE!!! DAMNIT
			$newPrice = 150 + ($webinarOriginalPrice * 1);
			$howMuchText = '$' + ($newPrice * 1).toFixed(2);
			$howMuchValue = ($newPrice * 1).toFixed(4);
			$('[name="input_34.2"]').val($howMuchValue);
			$('#input_31_34').text($howMuchText);
		} else {
			$howMuchText = '$' + (1 * $webinarOriginalPrice).toFixed(2);
			$('[name="input_34.3"]').val(1);
			$('#input_31_34').text($howMuchText);
		}
	}
	// Attach event handler to select box that will update the price
	$('#input_31_30').keyup(function(){
		webinarChangeEvent();
	});

	// Do the same thing but during load
	webinarChangeEvent();
/********************************************
 * END: Webinar Logic ***********************
 ********************************************/

/*******************************************
 * BEGIN: Submit button logic **************
 *******************************************/
$(":submit").click(function(){
	$(this).attr('disabled', 'disabled').val('Please wait...');
});
/*******************************************
 * END: Submit button logic ****************
 *******************************************/