There are a lot of variables. It really depends on how in-depth you want to get, how much bodywork or rust repair needs to be done, whether you’re taking it back down to bare metal or not, quality of materials, etc.
Mine was pretty involved - strip to bare metal, discover lots of old damage, straighten out metal and do bodywork on almost every panel, multiple stages of priming and sealing and block sanding, painted with PPG Deltron, cut and buffed. It took about a year and a half and cost around $9k. And this wasn’t a shop, it was a semi-pro / hobbyist guy at a very reasonable hourly rate ($35/hr) plus materials cost. The paint materials themselves cost nearly $2k… crazy. I could have gotten cheaper paint (Omni) for about a third of the price, but didn’t want to cut corners on that critical step.
So long story short, expect to pay at least $5k for a good paint job even if your car is straight and rust free.