I cant co-lo because i dont live in a cool country! In my country theres only 3 ds3 and are owned by the local telco that is the biggest isp here.

I started a webhosting bussiness with a Cobalt. So, my question is: Am i able to grow as a big webhosting company (very profitable) without co-lo? Only getting dedicated server and paying for it?

In the future you could have your server collocated outside your country. If you have remote access and remote boot it really doesn't make a difference where the server is.

Ok, but whats the advantage of having co-lo instead of dedicatedserver?

Well one I would say is the cost. With most dedicated server packages you end up paying way more then the server is worth. The second is that you have more control and customization of your own server.