Stay in Saint Germain en Laye or Paris

Take the Airbnb at $120 night for more than one person in Paris. There is nothing to see or do after a day in St Germain en laye. It will probably be hot doing all that commuting.

No way that I'd want to spend all that time ( likely an hour each way) on a train every morning and evening. Not for 120/night. It's not just the cost difference. On vacation, your time has as value too. I'd much rather sip a cafe au lait in a nice cafe instead of cramming into a train with the morning commuters. Or sit at a sidewalk table sipping wine instead of trying to catch the last RER out of town each night.

The other two posters have it right. There is so much value to being right there in Paris for an early coffee and pastry in the morning or a late stroll along the Seine after watching the ET twinkle late in the evening and a glass of wine at a sidewalk cafe before retiring to your hotel. I appreciate the idea of saving the money but It would be worth the $120/night to me, not to mention not having that long train ride morning and evening.

We spend 5 weeks in a suburb of Paris a few years back and it quickly got quite old, commuting back and forth every day. We were about 40 minutes out from the center. The cost became a consideration for us - it adds up fast. That said we did enjoy the quiet of being out in a leafy neighborhood where we could walk through the woods or be in Versailles in a hop skip and a jump. If we didn't feel like going in to the city it was very easy to just pick another destination for the day without tangling with traffic and crowds of people.

Piling on here. Always stay in the place you come to see. Don't stay in Mestre and commute to Venice; don't see in the suburbs and commute to Paris. Much of the joy of Paris is being there -- to run out and get the morning bread at a nearby bakery, to be able to take a stroll by the river after dark etc etc. spending time commuting -- meh. We have visited St. Germain en laye -- would never want to spend my visit to Paris there.

Thank you all so much! Glad I posted this question...you are tipping the balance :)

Here is the guide to mass transit, with its interactive planner: https://www.ratp.fr/en

You can see that from the town into a central location such as Gare du Nord, it estimates travel at a little over an hour, with several changes.

What a hassle.

You can see many posts here and elsewhere about the city's crackdown on short-term apartment rentals and what is required for such a stay being legal.