I was wondering what if any is the word in terms of availability, 
collectibility and potential liability (in terms of assessing whether
or not the item is legit and not fan made) of cels created for Magazine 
covers, etc.?  Like the Dragonball cover of Goku in the literary Son-Goku's
(Monkey King's) garb.

I've heard that studio animators do the work, and in some cases several test cels
may be created before one is approved and used.

Any information would be supremely appreciated.

Thanks!