I can do this fast for you, in approximately 1-2 days.
If you see my portfolio you'll note that the work is of a great quality and my reviews are all favorable.
My price is a little higher than your specified budget, this is because though it's a short clip, the work will likely still take time, sourcing the splats, muzzle flashes, etc.
I'm a professional in After Effects, and capable of getting the work done accurately and quickly as mentioned.
I'm looking forward to hearing back from you and getting started.
Best Regards,
Jacob Dodd
Professional Animator