First zoom lens

[USNFilms]

Hi all,

I have a canon rebel t3i and a 50mm 1.4 and kit lens (18-55mm) and would like to purchase a zoom lens for, well, close up shots from far away.

I film short action films with vfx and airsoft guns and I need a lens that can zoom in far so I can get a sniper scope point of view. the filming location is the one used in my previous video here.

I don't know much about lenses or zoom lenses so if you guys could give me some suggestions or advice that'd help a lot! I don't want to spend more than $400 if possible.

I'm considering the EF-S 18-200mm f/3.5-5.6 IS

Thanks