Back of the envelope, i get 7680 frames to process, one minute each which is just under $1300 for a medium windows azure instance. Not cheap, but probably doable. I'd bet you could spend a few hours fiddling with large memory instances versus medium, and find a sweet spot.

Set aside $50-100 a month, it'll probably be a lot cheaper in a year. (assuming optimizations and cheaper cloud services)

Or you could just buy a computer and stick it in a corner running 24-7. After it has finished selecting/rendering, you have both a video and a computer you can use afterwards.

Yeah, I'm more likely to go with this option, rather than spend over a grand on a video that may end up looking like crap anyway.