My old house in Dallas had a Federal Pacific panel in my daughter's closet. My (ex) wife inherited some money and bought a hot tub (which is like boat $$$, except the water is on the inside). Turns out it needed a double pole 60 amp breaker and I had already run a sub panel into the garage for my welder and power tools.
So we called an electrician about possibly upgrading and moving the panel. He never came out to look, but the phone conversation went something like, you have old wiring, undersized and no grounds, you'll need GFCI/AFCI and well have to rewire your whole house, you'll be without power for two weeks, etc. etc. $16k in 2005 dollars.
I'm not saying do it yourself, just be prepared.
We did it ourselves. Hung a GE panel outside. Replaced in the inside (sub)panel with another GE box for everything we couldn't move.
I was never planning on moving or selling the house, but ended up getting divorced, gave up the house and my ex let it go into foreclosure. If it was a problem, it was someone else's problem.
I have another house that we are slowly remodeling. I have a retired electrician doing some work for me at our business, so when I get all the wired pulled in the house, he'll inspect the plugs and switches and tie in the breaker box and give his blessing to it.