You can call a few electrical contractors and ask for a "ballpark" figure. Tell them you will not hold them to it, you just need to have something for your budget on the house.

Look for ones who are local and have been in business for quite a while - you want age and experience, not a big fleet of trucks.

That estimate will change, depending on difficulty of access, but if they completely abandon the knob and tube and give you a reasonably modern setup, they should be reasonably accurate.

Whatever they tell you, add 50%

Sounds like a beautiful old home and a neat opportunity for somebody. As for your question, it depends a lot on what you mean by "worth?" Are you asking whether it's financially worth it, or whether it's worth it to you? If it's the former, you need to ask somebody who knows local real estate and costs of remodeling extremely well. If it's the latter, well, nobody can really answer that but you.

I've completely rewired two houses from knob & tube in the Seattle area- the most recent one in 2008 for a ~1900 sq ft house and it cost about $14,000. Prices have probably gone up since then, and they may be different in your area. I'm sure any electrician in your area would be glad to give you a quote.

What they may not tell you is that they will leave holes all your house. Usually these are 4"-6" round holes, and how many and where they're placed depends a lot on the electrician and how much care they put into preserving your walls, so it's worth asking. If the walls are old plaster and you want to preserve that (especially important if there are details like cove ceilings involved), then you'll need a plaster pro to come around after the electrician.

You don't mention plumbing, but my guess is you'll want entirely new plumbing, and the same is true for plumbers- in both cases the contractors are in the business of making holes, and not necessarily repairing them.

The cost of a new kitchen can vary widely, and can be a fantastically expensive project. Once you start seeing the old custom details that are built into the rest of your old house, you may want to match some of them in the kitchen. It's about then you'll start realizing that the quality in older homes involved a lot of labor, and labor adds up fast in today's market. In other words, you're not going to be able to match the quality of the rest of your older home with the price quote you get for a home depot kitchen. A lot of the cute traditional kitchens in magazines cost $100K +, mostly because there's so much custom work involved.

I absolutley love and treaure old houses, and have fixed up two. But I'm still not sure they've made financial sense. My gut tells me they haven't, but the math is somewhat impossible (as it involves guessing the appreciation of your house both with and without the remodel) and frankly, I don't really want to know :)

I have gotten a lot of personal joy and satisfaction out of fixing up older homes. It feels like I'm bringing back a beauty and craftsmanship that is unmatched in today's market. I have also treated it more like a hobby, and have enjoyed spending my nights and weekends on forums like this one (not everyone does!), and don't mind living in dust when I know it's part of a larger vision. These things are definitely true for everybody and may or may not be true for you - best of luck with your decision!

Finished or unfinished basement?

An unfinished basement makes rewiring qiock and fast with minimal wall damage, especially in a single story house.

Any electrician that cannot use the existing receptacle locations in the wall should not be hired.

All you have to do is find the stud bay in the basement ceiling ad drill a hole to pull new cable (unless you are in Chicago ad are required to use conduit, and even that is not bad wth an unfinished basement).

If you have a second flor put a sub panel on the second floor and then run up into the attic and drop from above as needed.

You may have to sacrifice a stud bay of plaster fr the panel and smother one under it to get to the main in the basement.

Make sure the electrician is 'old house' and plaster savvy or your wall repair bills will swamp the electrician's bill.

Knob and tube (AKA K&T) does not have to be removed, just disconnected from its power source.
you cam leave the abandoned wires in places (and the cleats).

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in both cases the contractors are in the business of making holes, and not necessarily repairing them.

Some contractors leave fewer and smaller holes than others. :)

Look for a plumber who is experienced in "re-piping" older houses.

basement is basically unfinished or worth a tear down. here is the fireplace wall in living room

Cute ... and if you have basement access in a 1-story house everything gets much easier to do.

I had a 3-story Victorian wiring upgrade for the apartment's kitchens and bathrooms and it was only possible because there was a "bell run" where the wires for the servant's bells went from attic to basement.