how much would it cost to have a company

[monkeywiener]

make a web site as complicated as this one for example? and how long would it take them?

[emilia-faye]

3 million pounds and three years.

[monkeywiener]

really? oh ok that sounds fair enough.

[Lil O'lady]

I think provided you have access to the right kind of server hosting, or own and can manage same for yourself, the rest is relatively cheap. I appreciate relatively cheap is not quantifiable.
You need to look at hosting companies that provide this kind of interactive facilty and look at what they are charging. Many sell templates for forums as part of their hosting deal.
Of course, the cost in AB's case and many others will be offset by the advertising deals and this is a route that one could explore if starting out.

[fo3nix]

This site just runs some customised forum software.

I could build a similar site in a day or two, and have it running on a reliable server for �50/year, including everything except my charges for development.

And it wouldn't have the stupid errors that appear all the time on this site.

Thing is, I really don't have the time and can't be bothered. There's also the network effect. This site is popular; it would take more than just me making a clone to make it as popular and generate the revenue from adverts that this site probably makes.