There are lots of budget hotels in and around CDG in the Ibis chain, most I was finding around EUR 60.00/night. Modest would be a good word to describe the chain, which is part of the Accor empire. More info at

www.accorhotels.com

I stayed at the sister brand, Novotel Les Halles and pricier, but much better location and more perks like pool, etc.

You shouldn't have too many troubles finding availability, as hoteliers in France hurting somewhat from drop off in American tourists. Enjoy your getaway!