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Note... please only use official names here.

The names on the packaging and instructions -

Star Saber
Autobot Saber
Brain of Courage
Victory Leo
Victory Saber
Holi
Autobot Fire

Also - Robosen Optimus was not by Hasbro, it was just a licensed product, so if you are counting licensed items, Victory Saber would be a long way down the list of most expensive items.
However, if you are counting Official Transformers toys, some Masterpiece toys were more expensive than Haslab Victory Saber (such as Beast Megatron and Version 3 Convoy).
Unless you are only referring to Hasbro Transformers, then I think it is the second most expensively priced (RRP or primary outlet pricing).