Have you set a real budget for this project? 'average' doesn't tell us much.
If you fill out the form in *How To Ask For New Build Advice* you'll answer all the standard questions that help things get started.
You have a requirement for a "high end graphics design and animation workstation" and you also have a low end design / animation workstation budget.
With $1000 you're looking at a pretty standard personal PC build and not a high end workstation. You can still do graphics design and animation work on it - just not at the same level that professionals work at.
Is this a hobby or are you earning a living doing that kind of work?
I also have a problem sourcing parts and checking prices in Nigeria without knowing what's available locally.
Where do people get parts in Nigeria?