Not sure if they give you the renewal discount on the upgrade difference but probably? Someone else would have to confirm that for me. They *should* considering you can renew at any level. (Also, there is no child AP price difference, FYI. )
So, to upgrade, it would be NEW AP upgrade = (899-699)*1.065 = $213 RENEWED AP upgrade = (764-594)*1.065 = $181.05