I always used to go biking in the Alps for 4-5 days for around £350 (for 9 years). This was until last year where the cost escalated to £550. This was because I let my mate book some scabby, yet expensive hotel in Chamonix. I can’t blame him entirely though: a breakfast in the hotel was 11 Euros and was pretty lean. Elsewhere coffee and croissant cost 6-7 Euros, whereas before we had been to a place doing a full monty for 5-6 Euros. Add the weak pound and ripoff beer prices, we decided we would take a year off from Europe!! Oh and basic pizza like a Marguerita had rocketted from around 8-9 Euros to 12-13. No thanks!!
The best accomodation is a self-catering apartment IMO. Try Piere et Vacances. September will be cheaper than July which is when we normally go. We tried September in the early days but switched to July because we thought the weather would be warmer.