I usually buy 3-7 new 3dsky assets for every project, as clients mark there for me models they like...
It is really hard to compete with $6 price tag though.
Why don't you try just to put the pure white material in the GI overide slot of the overide material, and than calculate the GI again? That should solve your problem!
Why don't you chunk the animation in smaller parts, something like 500 frames? Halfing the resolution for Irr map and LC with smaller animation segments can be the way to go!