Nevermind, I was able to solve my problem.
I created another recordset on the optionvalues table, and filtered on OptValueName = $_POST['name-of-select-field'], Then I moved the query into the add to cart function just after the <?php tag. I added $row_optPrice1['OptValuePrice'] into the ecart object field for Option1Price. Now when I press the add to cart button, it creates the query for the option price based on the value selected and populates the Option1Price field in the ecart object. Everything passes to the cart just fine now, and the final price shows the added price from the option.