The cutscene from the video seems pretty straightforward. A few simple animations to move the planes and tanks forward, and few walking variations for the soldiers, and a simple sway for the flags. Position everything in FPS Creator, loop the animations, and use a screen recorder to capture various scenes in test game, then patch them all together in Movie Maker, and sychronize sound effects with the video. That would be my approach, at least.
If I could get Blender animations into FPS Creator (haven't gotten the time to look into it yet), I'd put my estimate around $30.00 or so. But that would only be for the animations, and video editing. It would be a different story if you were expecting all of the level assets modeled as well.
I would take Ocho Geek's advice in this case. 99% of game projects that are started here are never finished. It would be a shame to spend $500 on a bunch of cutscenes, and then lose interest in the project half way through. Finish your game's story, level design, and everything else until you invest in cutscenes. Just my two cents. Good luck.
Kravenwolf