Advice for a trip to Paris on a budget

Unfortunately you’ve chosen what is arguably the most expensive month of the year to visit. But yes, Paris has gotten almost prohibitively expensive since COVID.

I might look for a hotel in one of the outer arrondissements, the 9th or the 11th can be terrific. In fact, I choose to stay in the 11th. Have a look at Booking.com and, after you enter your criteria, concentrate on the results located in arrondissements other than the 1-8 arrondissements. They’re quite likely to be less expensive.

It’s also unnecessary to eat at restaurants every night. Buy some charcuterie, fruit, cheese and a baguette and have a picnic. Or eat in your room if it’s allowed. You might also try eating your main meal at lunch rather than dinner. Again, often less expensive. Ethnic restaurants, Moroccan, Lebanese or Israeli, serve excellent food, often at much lower prices than French.

There are lots of ways to conserve if you look for them.

I have been there about 10 times since 2002.
I stayed primarily in hostels away from the center (bunk beds bathroom down the hall type) the first 5 before higher income afforded me hotels. What is expensive to you?

I am seeing $55 a night beds with breakfast included) in shared room currently on this site
https://hihostels.com/

Consider a hostel (pick one with kitchen facilities). I have used hostels in Netherlands, Germany and Austria with positive results.

Regarding food: a fixed price lunch as your main meal of the day, cafeterias are often a good value, make dinner in your hostel (if you go that route), shop at a market for pre-made or easy prep meal. Please note, if you do a picnic lunch or dinner be aware that public drinking and glass bottles are generally prohibited. You will see people doing it, but it's my undertanding that it is illegal.

I agree that September is pretty expensive. Are you locked into that time frame or can you put your travel off a couple of weeks? I was going Oct 1 but decided to go a week before that to make sure I met with some friends. I was shocked at the difference in costs at my "regular" hotels in those 2 weeks with the October costs going down by about a third. Now, as hotels are booking out for Sept/Oct I see some nights at one of "my" hotels with costs being in the 550E plus range whereas at the end of October and beginning of November I see them down in the 192E range.

Where are you looking for hotels and in what area would you like to stay?

IF you are interested in museums, those prices do not change based on seasons. Many of the City of Paris museums are free (Carnavalet, Resistance Museum and others). Churches are free although Notre Dame has a timed entry system right now - tickets are free they just want to regulate numbers. Gardens are free.

What kind of activities are you interested in?

You might also check your local library for guide books to Paris. You can peruse them without spending any money.

editing to add: And now after a teeny bit of googling I see your user name attached to an AI site. Are you doing some kind of AI research/dive here on the forum or are you actually looking for help for your own trip?

What is your budget per night for hotels? What is your budget for meals? It's hard to recommend anything with just "on a budget" as the guideline because that phrase can mean different things to different people

September in Paris and budget don't usually go together. What are you looking for price-wise?