Then how did the custom argument come around? It sounds more as the guy trying to trick a potential buyer through deceit rather than selling it as a high price custom like FrenzyRumble or others.
Unfortunately he is not alone in the Ebay world. I have seen so many figures being passed as mint despite having serious flaws.
It typically goes like this:
Transformers xxxxx C9 condition - Mint L@@k!
But when you actually look at the figure it has massive paint scratches, missing parts, etc. Sometimes they even try to hide the missing part in a picture, I remember this guy selling a headless Doubledealer as 'mint' by using the vulture head for the robot mode.
Some years ago there was an Australian dealer (forgot the name) who was notorious for doing such things. She used stock photos rather than real ones of the toy and announced the figures as 'Complete 100% C9 mint!' I bought what appeared to be a very good TM2 Megatron but upon receiving the toy it had missing missiles, severely chipped chrome and missing parts of its beast legs.
Thankfully she refunded me in full but she should have known better rather than wasting my time. It only required some common sense to be able to tell that the toy is not in the advertised condition.
That's far too common in the ebay world.