No one is selling ‘new’ logic boards for this system any more. Apple stopped getting them made about two years after the system was discontinued (~2015). while some Authorized service shops might have a single board or two of the original spares kit for the system that’s a very slim possibility! Beyond that Apple repairs what they can of the returned bad boards to then ship back out (refurbed) so its hit or mis on getting a new board.
Buying on Amazon, or eBay has its risks too! Aliexpress is no different. These are the last places I goto for parts.
I’m sorry to hear you had a bad experience with MacPlace. How about using a different Mac parts house. I personally use iFixit, BeetsTech and TheBookYard.