Assuming you have a 200A service, you don’t need to replace your panel. You can remove two single pole breakers or one two pole breaker, install a 100A two pole breaker in the empty space, buy some 3/#1 copper SER cable (two hots and one neutral for 240/120V) and use it to feed a $125 100A load center without a main breaker.

You need to use #1 copper for a 100A subpanel, you can use 3/#2 aluminum cable for a 100A service entrance but there’s an exception that allows using wire rated at 83% of its ampacity for a service entrance conductor which does not apply for subpanels.

Refeed the two removed breakers out of the load center and add a 60A two pole breaker to feed the EV charger, if it’s a cord and plug charger that you plug into a NEMA 14-50R you’ll need a GFCI breaker, if it’s hardwired you don’t need a GFCI breaker.

The material can be purchased for less than $500 for this project, if you have to hire out the labor it’ll be considerably more expensive, I’d estimate one day for an electrician or around $1200-1800 depending on where you live.