I'm booked to fly long-haul economy with Iberia for the first time. Manage my booking allows me to select seats, but with a charge for any seat not classified as "Standard". Is free standard seat selection the full privilege that IB offers OWE travellers, and do the price tags for other seats apply? If that is so, do I have a chance of getting assigned a better seat at premium check-in at LHR, or would they be instructed to collect payment for that?