Paris

Gary - The city of Chartres with its iconic cathedral, can be a good option as a base to stay to be near Paris. The train to Paris from there is just little over an hour. Saint Denis, which is a suburban city of Paris, makes an ideal place stay as well that is convenient to Paris. It's just a 30 minutes metro ride to Paris from there. A visit to the Basilica there is a must. Lodging in Saint Denis will definitely be cheaper then Paris.

http://ee.france.fr/en/discover/saint-denis-1

Hell from Wisconsin,
Outside of Paris the housing is less expensive. but if you total the value of the time of your trip devoted to train travel and the price of the train tickets...and getting from where ever you are touring in Paris to the train station you require to get back out of Paris...staying in Paris might be a better 'buy'.

I would heartily recommend an over night or two in Chartres. Les Conviv'hotes is a nice BNB where Sylvie Menard speaks excellent English and puts out a great breakfast.

I am in Stevens Point

wayne iNWI

I'd strongly recommend staying in central Paris, i.e. in one of the 20 arrondissements inside the Peripherique. All are well served by Metro, putting all the sights in easy reach. The ones farther from the river will generally have lower hotel rates for comparable accommodations. Use booking.com to look for places, it has good filters and lets you search by map or other criteria. Ideally you'd be close to a Metro station where two lines intersect, giving you more options to get around faster.

I would not stay in Chartres to visit Paris, the train is quite long and only takes you to Montparnasse, which isn't within walking distance to main sights. Chartres is a good place for a 1-2 night stay for its own merits, however.
Saint-Denis, mentioned above, is quite rough outside the immediate vicinity of the Basilica. Not recommeded for unseasoned travellers.

As stated above, if you mainly want to visit Paris, stay in Paris.
BUT if you just want to have the option of going to Paris while staying in an interesting location, I would recommend Versailles even though you've been before. There is a lot to see and do beyond the Palace, there are many places to visit nearby, and the C train takes you directly to many sights in Paris (Eiffel Tower, Latin quarter, Orsay / Louvre...).

Paris is a great deal more than just sites.

If Paris is your destination, stay in Paris. You miss too much by attempting to see Paris and by staying elsewhere. Valuable vacation time is compromised as you travel back and forth, not to mention the possible extra transportation cost. If budget is a concern, there are many fabulous hotels in Paris which are not at all expensive.

I also disagree with RJean. Chartres trains aren't cheap. Tickets for tomorrow (on oui.sncf - I think that's the official site) are €18.30 each way, trip is an hour to 1-1/4 hours and the train only goes to Montparnasse. You still have to travel by metro to get to most sights in Paris. If you want to enjoy a late evening in Paris - dinner, a Seine cruise, a neighborhood bar, or even see the beautiful old buildings and bridges illuminated, that makes for a very long day. The sun sets relatively late. If you're going in March, it's around 6.30-7.00, but when DST kicks in at the end of the month, it'll be 8.00 and by May 1, it's after 9.00.

Saint-Denis is much better for transportation, but as others have said, much of it is unsavory - not the Paris most tourists want to see and you may not feel comfortable coming back late at night.

If Paris is your destination, stay in Paris

...particularly if you are coming in the next few months when pension reform debate will encourage continuing strike activity in Paris. Public transport is usually the focus, and I wouldn’t risk staying in the suburbs and sharing potential commuter problems at this time.