I had wondered where the scam was here, the penny would have dropped when they sent more than asked for.
Yes, that's one of the oldest ones ...
The secret is not to let the scammers know you know they're scammers ...
If you do they will learn from their mistakes and improve.
They have improved considerably over the years, but it's amazing how many people still fall for them.
The adage 'a fool and his money are easily parted' is true, but when someone is desperate (for love) it can be only too easy to be scammed.