Listen I'm not an expert but this snake has the exact same break in the line on the head and horizontal dots. Ad was last updated just two weeks ago.
Not trying to be a pessimist but the chances of someone abandoning a 600 dollar snake when moving or losing it and not looking for it?
For picking up a mainland female reticulated python, one of the snakes with the highest level of care requirements there have been an awful lot of concerning basic knowledge questions. People on this forum have been kind but I'm assuming there would've been some questions outright buying a male to breed. Saying your neighbor found a 600 dollar snake though plays a little easier.
Wow... The patterns and line breaks on their heads do appear to be identical...