Salut
côté logement il y a aussi les auberges de jeunesse qui sont une solution possible, j'ai mis un post à ce sujet sur le forum international de SIF, j'ai la flemme de retaper en fr alors le voici en anglais :
I put the information here as it may be useful for other people too !
So the website is :
http://www.aijparis.com/framea.htm
It's very well placed, near Bastille (in fact it's near the subway station of Ledru Rollin but it's something like 10-15min walk from bastille), so very close to the center of Paris.
To go to the RIP from there you have a Bus (76) that goes directly near the RIP

it's something like 25min away. (There is also the possibility to go via the subway, it should be less than 30-45min max).
Prices are also quite low so i guess it's the cheapest way to stay in paris beside staying at a parisian player's apartment.
Prices : from 19€/night (in a dorm) to 42€/night (private room)
Limitations : you must be less than 35 years old, you cannot stay more than 6 nights. (and I guess you should be able to sleep even it's a bit noisy

but I doubt Paris will be full of tourists in late october)