I am writing a business plan for a website service and am trying to get some figures for development costs for the financial section of the plan.

The site will match customers with event vendors and packages compiled by the site (e.g. think vacation packages on Expedia but instead event packages including things like music, food, venue). The matching will work similar to eharmony (not dating of course). Customers will be asked to select the types of vendors they need for their event, the date of their event, etc. They will then specify criteria for each vendor type. Vendors and packages will be selected for them based on matching of event details to vendor profiles already on the site. The site will also have vendor listings with ratings and reviews from customers. Vendors will be able to use an app that synchs their calendar (Outlook or Google for now) so they can see when they have been booked by a customer, as customers will book and pay for the services through the site.

I know that isn't much information, and if you need more please ask.

Any idea of how much a developer or developers might charge to develop something like this? How many developers might it take and about how long?

Estimates are ok.

If this posting is not in the correct forum, please direct me to the right one. I looked through all of the titles and this made seemed to make the most sense.

Thank you!