I'm a 2D animator, my style is similar to a cartoon called "Invader Zim" but I have worked in many styles. I see this video in a similar style to "Ren & Stimpy".
I'll charge $25 for a second of animation, roughly $1 per frame, and $225, for the full 7 seconds, (less if it works out shorter) + freelancer.com 10% fee. No payments necessary till you've approved the final product. I'd relish the opportunity to work on this with you.