Hei, Frid,
Contact Le Rocher, +33 476 70 96 46, mobil +33 6 07 65 27 28, around 15 to 17 EUR/night, perfectly locted, next to the telepherique, main lift.
Also try Le Vieu Guide, +33 476 79 90 75, also about 15/20 EUR/night, on the main street.
I suggest dealing with them a better price if you are staying as long as a month.
Sadly Le Refuge has closed and converted into apartments.
I remember reading that there is a Swedish guy there who has a hotel there.
Tourism office: +33 476 79 90 05, www.la-grave.com/english
Hils from the hills,
Rich