Monetti Taxi updated fare for Amalfi coast?

I don't think it's out of line; prices have gone up post-pandemic as well as the cost of petrol.

Similar examples: Top Excursion (which has seen some recommendations on this forum) is charging € 660 and up (depending on pickup point) for an 8-hour tour of the coast. Similar to the tour you may have been referencing, this is for the car/driver only; no tour guide although the driver will probably point out some spots of interest. As well, if the driver resides on or very near the coast, he'd have to drive to the port for pickup, then back to the coast, then back to Naples to drop you off, then back to the coast again. It's not what I consider a short distance, either.

https://www.topexcursionsorrento.com/en/private-day-tours

This individual was quoted a rate of €640 euros from Ravello Cabs two years ago:
https://community.ricksteves.com/travel-forum/italy/private-car-for-sorrento-and-ravello

If too much for you, Mondo (endorsed by Tick Steves) has a shared tour from the port that's quite a lot less expensive:
https://www.sharedtrips.com/shared-shore-excursion/napoli/1/amalfi-coast-max-19-people#tour-details

hey hey fmcbenson
welcome to the forum
Kathy is right on about prices going way up on lots of things. the cruises i've been on we registered on cruisecritic.com (it's free), went to forums to find your ship's roll call with date & ship. cruisers will post about sharing cruise excursions at different ports, ask if anyone interested and join the group. let others investigate tour companies, i was nominated for that job LOL. looked up local tour companies, sent email for info/cost/where it goes, ask cash or credit card excepted, pay at end of tour. be very adament about getting back to ship before it sails away. wanted smaller tour 6-8 people.
what's the earliest you can get off the ship, meet up with others on tour, tour waiting outside of disembarking, how many other ships in port can add thousands, is it a docked or tender boat port?
cruisemapper.com
website that shows the ships in ports that day. look up your ship, month, days gives you an idea how many people will be trying to do the same thing you are, can get crazy. may 13 from civitavecchia (rome) there are 6 ships arriving or departing. the port is over an hour from rome city center, know exactly how you will get to port, how close to ship you can get. trains and shuttles will be crowded, years ago we found a cab near piazza navona with a cost of 140E. had a large protest, roads blocked, hard to get around and found this lone cab to get us there with whatever it took, expect the unexpected. plus it's jubilee 2025 in rome with millions of people expected. hope you're spending couple days in rome before cruise.
wishing you great and happy thoughts about your cruise, once all comes to order no stressing. have a fabulous time.
aloha

That’s a very long distance in heavy traffic, a lot of time, stressful knowing you have to back at the ship by a certain time with traffic the length of the coast, and round trip. I don’t think the Monetti family has overpriced this.
We had them drive us one way to Sorrento with a stop at Herculean on the way and then transfer us back to Naples from Sorrento a week later two years ago. Prorated per hour , it came to more than what you are being charged.