Getting from CDG to Gare st. Lazare

Of course, your actual fares will be in Euro. The flat rate taxi fare from CDG to the Right Bank where Gare Saint-Lazare is located is 53Euro. I suspect it will take more than 29 minutes to get there.

On the RER train in to town, be aware there has been some construction on the line so it's closed some days with a bus work around.

I'm one that just does a taxi in from the airport. I'm tired, don't want to fool with going up/down stairs, changing to Metro from Gare du Nord to Gare Saint-Lazare. I'm spending way more on my vacation and can work with 53/58E for taxi fare.

The Roissy bus is also likely to take longer than 1h3m as you'll need to transit from the bus stop in the Opera area to the train station. BTW, here is a link to EasyCDG with the current fare which is more than what that website says.

https://easycdg.com/roissybus-paris-cdg-de-gaulle-airport/

You have laid out the pluses and minuses of the three main methods. Your prices are wrong but post 1 is pointing you in the right direction. I take the Roissy bus because it avoids having to connect from the RER B to another train and I hate being underground. Not that the connection is difficult but I like getting on at one stop and getting off at the end of the line without having to make a connection. It’s been a while but I don’t recall any stairs during the train trip. If you are pressed for time, I think the train is your best option, not a taxi. 29 minutes from CDG to Gare St Lazare might happen at 3 AM but is highly unlikely on a regular day with regular traffic.

The Roissybus is more expensive than what Rome2rio is telling you; the fare is in the vicinity of 12€/person - a little bit higher than the RER.
So, for 2, a taxi only costs 29€ extra. I'll let you decide if that's worth saving - it depends on your constraints!

the internet is full of bad information around Paris taxis -- the top hit talks about 'estimates' ranging up to 70 Euro when the fare has been fixed for years -- right now at 53 and 58 from CDG.

The train and bus rates are ludicrously wrong which reinforces my previous sense that Rome to Rio was not a reliable source of information. Train is 10.30 and Roissy Bus is 13.50.