What are these pearl worth?

[PinkyPig]

I am recently very into pearls and looking at both south sea pearl and the Akoya ones. These are the two I saw online and wondering if they’re real pearls and is it worth to buy? If they are, what sort of price are they sitting?

I suspect the first one be the south sea pearl?

Is the second one Akoya pearls?

 

[Pearl Dreams]

Can't tell from the photos-- they could both be fake.

 

[CortezPearls]

Hard to say with these images...impossible to see any details!
Now...are they stating these are pearls? What kind of warranty or return guarantee do they offer?