new business idea - clueless about marketting costs for it

[archie08]

Hi,

I am at the concept stage of a new business idea and I am stuck on my business plan with the marketting costs/budget

Let say I opened up a new website, This website would require thousands of people to go onto it to sell stuff. The idea (I know this may seem hard to believe) has not been done before (not in my concept anyway) so how would I project marketting costs for a potential investor??
Tottaly Stuck.....

It would be fully web-based, I know I could use things like advertising in magazines, talk about it on forums etc etc but whats the best way generate more traffic??

Pls help any advice appreciated

[max99]

are you sure its not been done before, ive had many an idea which I thought was unique tbut found out it'd been done before

[MrCatz]

I guess the OP is referring to a site similar to ebay or a cassified ad site. In which case, it isn't that original anymore