It should only take several hours for an electrician to disconnect the wires and rotate the box if that was all that was involved. However, it's hard to tell what all is happening in that box. For example, it looks like there are wires coming out of the bottom of the box that are going somewhere else, and there may also be some splices in the box that are not to code. How much these issues add to the time I can't say. Also, you are aware, aren't you, that the electrician will have to cut out sheetrock above and below the box to pull the wires through and then reinstall them once the box is turned? And you are getting a permit, right?

The other potential issue is that the wires on the left will enter the panel on the right (and vice versa) when the box is flipped. The wires may not be long enough to reach the same circuit breakers and may need to be extended, which will require extra time to complete.

I agree with kudzu9 that code violations would need to be corrected as part of this change, and could substantially impact the cost of the project.

Thanks for your reply, Kudzu9.

I've been in my house for 40 years, but the box was changed about 20 years ago to add 2 breakers. The splice is from the doorbell transformer (I think).

I'm thinking about adding a room (which would require a permit), so I'm trying to decide how many other projects I may be able to afford to have done at the same time. Of course with an older house, I can bet some type of problem will come up. But I think I will ask for a seperate estimate anyway.
Thanks for your reply. It will give me some questions to ask the electrician.

Thank you for your reply also, Kurto. Yes, I definitely would want everything to be up to code.

I've tried to familiarize myself with articles about moving a panel box, but most of it turns out to be instructions on changing outlets.

If any one has any other pointers, issues or questions I should talk to the contractor about, I would be happy to get them.

It's hard to say for sure from that picture But it looks to me like there is no separate ground in this panel? If true, I'm going to say that will be a problem for changing out the panel. Just changing out the panel would be a few hours, but If it needs a new feed run- impossible to say without being there.

If that is a sub-panel it is not installed correctly.

A sub-panel needs a 4-wire feed (hot-hot-neutral-ground) and the grounds and neutrals must be separated.