The value of a website: help me understand

[madcaptains]

Hi,
I hope this is on the right section of the forum

I was looking at sitepoint and I can't understand how people fix the value of the websites they sell.

Here is an exemple:


A website that generate revenue is a business. Who in the word would sell a business that generate 1000s/month for a ridiculous price like that! And it's the same for all sites I found. The 3rd one on the image is a great exemple: you buy it and it pays for it self within 2 months. My own business generate revenue like this and the last time I checked, it's worth over $150 000.

so what's wrong??