With just 3 days in Paris is it worth taking the time for a day trip to Versailles?
Also, what's the approx. cost of a taxi from CDG to the city centre?

taxi CDG- central paris should be, according to Paris Tourist office average of 40 euros 7am-7pm and 45 euros at night and Suns and holidays

Too short a time for a day trip to Versailles. See it the next time you go to Paris!
Taxi from the airport to the 7th on a Sunday for 3 of us with bags and tip was just shy of 50E.

IMO, definitely not worth it with only 3 days in Paris. Even with 10 days in Paris!

the cost of a taxi will depend a LOT on the time of day/traffic. From a low of about €40 up to €55-€60 if there is massive traffic.

As for versailles - w/ only 3 days -- and assuming this is your first visit to Paris I personally would not go to Versailles. You won't have time to even barely scratch the surface of central Paris let alone taking more than 1/2 a day out of the city.

I would think it would depend on whether Versailles was a priority for you or not. Have you been to Paris before? Are you interested in museums and great old churches?

Versailles is amazing and well worth a day. If you've never been to Paris before and have only three days I personally would not go to Versailles and hit it on another visit. For me, I would fill the three days with walking around Paris, seeing the most important and famous sites and museums, eating and drinking, sleeping as little as possible. Versailles has been there for 300 years. It'll be there on your next visit. Ultimately it is a personal choice.

I consider Versailles to be a part of Paris - 30 mins or so each way on train right to palace - a wonder of the world. Go for it as it may be the most memorable part of your Paris sojourn. Especially the park and gardens. Investigate the Museum Pass good there and for faster entry

If you haven't already, you might want to consider all of the alternatives to get you from CDG to central Pairs...Roissybus, Air France shuttle, shuttle van, RER, etc...

Skip Versailles, only becasue of the time you have. If you arriving from far away, jet lag will affect your first day. Also, part of first day will be used getting to hotel, and large part of last day could be used getting to airport for flight. So calculate how much "on the ground " (pied à terre?) time you really have.

I would skip it. Save it for another trip. It is really a whole day, and, well, you don't have enough time in Paris as it is!!!

Given the staggering number of places of interest in Paris, I suggest you make a "to do" list of first priority attractions.

The question then arises: Is Versailles a first priority attraction? That depends on where your interests lie.

If a person had majored in European history in college, or has a major interest in the French Revolution of 1789, I think Versailles is required.

If a person does not know a Bourbon from a Valois or a de Pompadour from a de Maintenon, then I say skip it.

A similar evaluation be applied to any one of several huge museums and historical sites in Paris.

I say skip the Louvre if you have no real interest of what is there to be seen. One can get trapped in there it seems and wander for hours with a glassy eyed stare which in effect sees nothing.

I personally have never bothered to look at Napoleon's tomb. So he is inside 7 sarcophagi. I find other points of interest in Paris of greater priority.

Yet, for others, Hotel Invalides is top priority. So in the limited time you have, there is but one logical thing to do: Prioritize a list and see how your time measures up.