There are so many variables, it would be impossible to say without getting into the details of each job. Rough estimate…
$500-$1500 or more. Like me, $2100. I needed to upgrade from a 100amp panel to a 200amp panel. Village codes required it because I had no more room in the 100amp panel. And in doing so, the outside meter must be upgraded as well. That required the utilities to come out, shut off the power, then return after everything was rewired and turn the power back on and inspect all the work. So of course permits, lots of time, materials and so on. That did not include the JuiceBox 40, which I paid $600 for. I got mine hard wired into the garage. We ended up keeping the 100amp panel in addition to the new 200amp and reworked some of the bigger draw appliances to all go on the new panel and the basics on the old one. We ended up replacing the old 100amp with a new 100amp because of its age and some burned breakers that were unknown to us. When you start upgrading old electrical, it gets expensive. But now our home is safe and up to date. And we have lots of space for more breakers if we ever remodel or add on. Money well spent.