Buying and Selling Forums

I have once bought a forum and I have also sold a form once. Have you tried buying and selling forums? Did you spend a lot of money when you bought the forum? Did you make a lot of money by selling forum. I spent just about $70 to buy a forum. But when I sold my forums, I sold it for $600 (it was not the forum I bought).
 
I have never bought or sold a forum, however, I have seen a lot of people buying and selling forums. Even the admin of our beloved forum FE acquired two forums and merged with this one. I think it can be a profitable venture.
 
When you buy a forum, it's not about spending a lot of money. It's about a fair valuation of the forum, which can be very hard when it's not monetized.

When it's monetized, the calculation is easy. You normally pay for 2 - 3 years of net revenue, which is the proper method for online businesses.

When it's not monetized, the calculation is much harder. It's usually a hazy compromise