Based on this below from the sticky is there different costs to upgrade online vs. at the airport kiosk? If so is one or the other cheaper? Thx

Q: Can you get a standby upgrade to first class?

A: Yes. If there are seats available 6 hours or less before departure, you can before check-in. The charge for upgrading depends on the flight distance: 849 miles or less is $70, 850-1499 miles is $110, and 1500 miles or more is $270. The best deal (longest distance within the cheapest category) is SEA-SFO, which still falls within the $70 upgrade. Some have said that you can do it *during* online check-in (OLCI), but I have found that to never work. In fact, if you get through the first page of OLCI, the online upgrade seems to not work. As long as there is a seat, you can upgrade to it. To do it on the web page, go to the page where you can manage the reservation. There will be a checkbox that will allow you to check-in. Do not check it (yet), but note that it is there. If it is not there, you are not within the 24 hours (according to Virgin America's clock). Instead of checking that, press the button that says "change seats". When you mouse over one of the first class seats, it should tell you how much the upgrade will cost, and it should be the price above, instead of the fare difference. Go ahead and select the seat and enter payment information. After you are all done and your credit card has been processed, you can check-in.