How much would you say the monthly operation cost of a website like afternic.com to be? Where do you think most of the cost comes from? please give your estimates based on number of employees you think is necessary.

Thanks

AfterNIC.com?

As far as I know they have a site where they allow others to "auction" domains. This doesn't seem like a big operation. You could possibly run this on a single shared hosting account (cost: ~$30) with a one man operation. Depends on how much you can do yourself. The cost for a site like this could be really low.