I'm working on an idea for a travel site and could use some help from you guys in understanding the general time/costs associated with getting this up and running, as well as ongoing costs.

The site would be similar to http://www.reservemy.com/

I would like to utilize Google Maps functionality, along with a single page for each location (in the above example each page would have a separate hotel with general info on that hotel), that could be easily created by each user of the site (building their own page).

By looking at the above site, can someone give me a general idea of time/costs for this? How much time/$ developing? Could the site be hosted by something like Yahoo hosting service (at least initially)? At what point would it make more sense to purchase my own servers rather than having it hosted?

Any help would be greatly appreciated.