Upgrades: At the Airport, or at booking?

Good Afternoon to all on V-Flyer!
I have a quick question (which im sure has been asked many times before, but cannont seem to find the answer, so i apologise in advance!)
My friend and I are looking at flights to New York in late January. We're quite upset we missed the sale a few weeks back, but no point in crying about that! [:D]
I'm rather tall, so I'd prefer to fly Premium (Well, I'd actually prefer Upper, but im only a mere student, so I cannont afford that for every trip [:p]). I was wondering, in members past experiences, would it be better to pay for a Premium flight at booking, or at the airport?
We're also kinda holding out for another sale, so fingers crossed for that too.... [:w]
Thank You to all in advance! [y]
I have a quick question (which im sure has been asked many times before, but cannont seem to find the answer, so i apologise in advance!)
My friend and I are looking at flights to New York in late January. We're quite upset we missed the sale a few weeks back, but no point in crying about that! [:D]
I'm rather tall, so I'd prefer to fly Premium (Well, I'd actually prefer Upper, but im only a mere student, so I cannont afford that for every trip [:p]). I was wondering, in members past experiences, would it be better to pay for a Premium flight at booking, or at the airport?
We're also kinda holding out for another sale, so fingers crossed for that too.... [:w]
Thank You to all in advance! [y]