How much to create this website?

It is not that simple. How many members do you anticipate having?

What is the volume of traffic that the Web site will have to accommodate?

What kind of pages have to be created on their own?

What kind of activity will they generate (transactions like ebay?)?

You are not providing enough information for a web designer and developer to give you an estimate.

Oh okay. I`m not going to go build a website, but I definitely want to know the details of how this works.

For a start up
Members – 20k +
Traffic – 20k page views a day
The pages to create on their own will be something like Fluther, where someone opens a topic for real time answers. (so i figured it woould be an automatic process)

edit: Oh, and made to handle at least 20k people on at the same time, participating in live discussions like Fluther.

It sounds like you have an idea and want to get it up and running. That’s a great start.

Most web designers and programmers will walk through your idea with you, try to determine how long the work will take, and then either give you a bid based on that number of hours and their hourly rate or they will simply ask you for a deposit and track the number of hours they work on the project. A professional web designer/developer probably typically charges $40—$100+/hr. A reputable firm can charge more and typically you’ll have more people working on your project.

That development amount is going to be separate from your needs when it comes to hosting and maintenance. But they should be able to outline those costs for you as well.

You’re probably going to need to define the purpose of the site and what you will need a lot more clearly before someone can give you a good idea of the price. It may be best to sit down and actually try to sketch out the different functions of the site. Don’t worry about graphics or details at this point, just make a sketch of each type of page so you can start to get an idea of what all will be involved. If there is a site you like that is similar to what you’re looking to do, that may be a great place to start.

For an example, lets take one of your sections you outlined, “A membership feature”.

So some parts you might need
– login screen/script
– password retrieval (forgot your password?)
– member profile (create/update/remove)
– member settings (whatever the purpose of your site is, will each person be able to configure their own account?)
– permissions (who can do what on the site, are there different roles?)
– user tracking or history
– if membership is paid, you’ll need to work out a way for that to be purchased and paid for

That’s really just a quick look at one section.

Think it through, figure out as much as you can, and then start looking for the right person/team/firm to help you out.

On top of web-development professional costs, take into consideration the cost of operations, i.e. server up-time, redundancy/mirrors, back-ups, bandwidth usage, security, restoration of service in case of a DOS attack. . . . frankly, I don’t have a number, but these are some of the other cost factors.

$3000

Give or take 50% depending on how well designed you want it.