Thank you MKESCAN for stepping in to answer questions as best you can! I've been so busy with rebanding that I've not had the chance to check in as often as I'd like. As I will be retiring from Milwaukee County as soon as the rebanding project is complete, my time is limited. However, I do promise to stop by more frequently in the coming months to update as necessary.
The total amount for the analog system, first implemented in 1995, would be difficult to assess as the migration was slow and expansion based on user need through the years. I also believe it's not a fair comparison to base those costs, circa 1990s, with the costs for OpenSky. Our P25 migration, which is in the late planning stages, should have comparable infrastructure costs. Milwaukee County provides the infrastructure only to our users. The costs for subscribers - which quickly mounts - is borne by the muncipalities and agencies on our system.
*Added on edit: Also, we feel strongly that our P25 system will be 100% operational when we first flip the switch. We are putting in a tested and tried system - not allowing the users to be guinea pigs on the latest technology, which may or may not be proven efficient.
Last year, I worked with the Motorola team to determine a full cost for P25 migration - including subscribers. At that time we took the number of P25 capable radios, the number that were fully digital, and the analog-only to determine upgrade costs. The subscribers came to roughly $16 million at that time, with the infrastructure about half that. We now have more subscribers on our system than the city - so the overall costs will be higher.
(As just an FYI, the first P25 site will be closer to $2million because of all the one-time only costs of a master site. After that, they will be far less than the $1 million stated above.)