I'd get the cel, only if it was really cheap.  
Not being the original optimus really lowers its 
nostalgic value to me (its not the same prime I 
watched when I was a kid).  

Its kind of like the OVA/TV cels of the same 
character.  I collect Bubblegum Crisis cels, I'd 
pay an arm and a leg for OVA Nene cels, but I 
wouldnt pay more than $50.00 for even a great 
shot of 2040 Nene.  Its the same character, but 
not the same.