Windows Server with dotnet framework version 4.6 is required. Processor/RAM/Disk requirement would depend upon estimated usage and expected performance. 

The cost would be implementation specific. It may vary based on expected usage, type of models involved etc.

Again this would be implementation specific. Actually it takes more time to develop and deploy Code Model than it takes to install and configure the software on server. Minimally, the entire process would involve Software Installation, Configuration, Testing, Verification with one or more existing (proven) Models which may be followed by optional processes like Training to Administrators, Managing User Access etc. So it may take anything between three days to three months based on implementation specifics.