2-10 weeks.
Seriously. The "craft" of specing out hours depends on as much information as you can collect. That's what the Steps to Success program and education files are for.
Do you just need a project start and end date for your client or are you trying to come up with a dollar amount based on "man" hours, etc.
You have NYC and (I assume) northern NJ in there. If you need to do anything that involves a union, you might as well make it 20 weeks.
Setting up the servers is relatively fixed time. Two CCM's, round it up to a day.
Unity: 2 days. Depends on the AD / Exchange guy.
Unified messaging can be easy or a mess depending on the state of the customer's active directory. Problem is you never know until you are in the middle of the install.
Collecting information for the phones, its features, voicemail users, etc. Couple days to a week. Depends on the internal workings of the customer. Some customers can railroad the information through. Some customers take two weeks to determine who will be the contacts at the customer site.
Replacing LAN Switches? Depends again on what the network looks like. Closet with existing LAN switch with no VLANS, etc. 1-2 hours per closet. Closet where the customer did department VLAN scheme and every port is on a different VLAN (and you don't want to convert to recent best practices design) a day per closet after documenting, implementing and verifying.
Putting out phones? Depends. Could be an average of 5 minutes per phone for a typical office / cubicle and office type environment.
Other places where you have to be escorted by armed security, no tools, take off your belt and shoe laces, etc. 1/2 per phone.
End-user training? 1 hour session per 10-15 users.
We calculate installs based on the anticipated complexity of the install and experience from doing many installs in the past. Use time tracking tools to determine how long it took, etc.
What do they have for gateways and PSTN circuits? Migration plans of old circuits to new, flash vs phased cutover, do you need to order new telco circuits, etc.
Well, hope that gives you SOME insight to get you started.
