I currently have a home with 100 amp service to a 100 amp breaker box. The box is old and should be replaced, can I have a 200 amp box installed even though I only have 100 amp service?

Assumptions: Main breaker is in this panel.

Other info: Utilities portion usually doesn't cost you. Underground, overhead and where demarcation is in your area determines a large part of the cost. The actual change is co-ordinated, so there is little service disruption.

For overhead service, you usually bear the cost from the masthead to the panel, not including the meter, but including the meter base.

Some localities are requiring an outside disconnect.

If all that's changed is the main panel, then the main breaker would have to be changed to 100A. Not cheap. Order of magnitude $100. The 200 A panel typically has more spaces.

There is no easy way to answer this as not enough information is given.

You likely can't just upgrade the panel but the possibility exists that the wiring and equipment are rated for 200. I'd guess that's not the case but call an electrician to look at it and you may get lucky. More likely is that all the service wiring and the meter base will have to be replaced in addition to the breaker panel.

Edit- As Keepitsimplestupid said you can install a 200 amp panel with a 100 amp main breaker in it. That would let you upgrade the service at a later date but still replace the panel now.