It really depends on many factors.

If the electrician can simply add the right breakers and replace the existing wire, it won't be too expensive.

If the existing electrical panel is "maxed out", or if there is a long distance to rewire with no easy access from the panel to the kitchen, it will be really expensive.

Your best option is to get a couple of quotes from reputable, local electricians based on your particular situation.

The problem is that unless whoever ran the wiring to the gas cooktop anticipated that it might be replaced with electric, the wiring is too small (ampacity) to power an electric-only cooktop.

Running a new circuit doesn't have to be expensive. It all depends on how accessible everything is. Best case, the breaker panel is on the other side of the wall where the stove goes and it still has available capacity for another breaker. In that case, it's a $150 DIY job or maybe a $500 professional job.

Most houses don't make things quite that easy, which means it could cost a couple of thousands and two or three days of work, including sheet rock repair.

I'm located in Toronto and had to have a new wire run in my 1950's house, probably around 30-40 ft. I needed a new breaker but the panel itself had room. A portion of running the new wire was "easy" through unfinished basement (although many joists required drilling), but a portion was through the ceiling of a finished basement. The entire thing was done without cutting any holes and I was super impressed.

This was part of several different electrical things I had done, which added up to around 9 hours of onsite work. Total cost was $1100 for labour and materials, which felt like a really good deal for an expensive area. If I had to guess, the material cost for the new wire + breaker + labour were about 400-500$ of the total. The heavy gauge wire is no joke...