I'm taking an international flight on Delta to Amsterdam and back. When I booked, all that was available were middle seats. Just to get an aisle seat, I have to pay another $69 (and then to get one of the nicer seats with more leg room, it's $129).

All I want is an aisle seat -- do they open up for free at some point when people don't buy them? When? How can I make sure I am first? I don't have any status I can lean on to try to earn upgrades -- this is my first time flying Delta.

I just think paying another $70 on top of an already $1700 itinerary is sort of ridiculous, and I just lost my job yesterday so I'd rather save my money. It's 10 hours though, so comfort is going to matter.

Thanks!

EDIT: My trip is six days away. I'm looking right now and I see 15 Comfort+ seats and 40+ Preferred seats that are aisle or window, but they all cost money. I currently have one of the middle seats in the four-seat middle row. The plane is an Airbus A330.

Months later edit: I got to the airport early and they upgraded me to an aisle seat for free.