Hi, I reckon you should definitely check out the Route des Grandes Alpes. 680km / plan 3 days. Goes through some of the best rides in France (col de l'Izoard, col du Gali
, etc.) and the highest paved pass in Europe (col de l'Iseran, 2770m).
Also plan at least 2 days for Andermatt, the rides are great, depending on the weather. If you also plan Italy then you should go through passo Stelvio (second highest paved col, 2760m), passo Giovo and the Dolomites.
In Austria - if you still have time - aim for Nockalmstrasse, the Turracher Bundesstrasse and/or Grosslockner Glacier. All of these are one/half day and the Nockalm and Lockner are toll roads. Low car traffic but expect plenty of motorbikes. The roads are great.
For accommodation you should plan approx 20-30 EUR / day for a normal double room with parking possibilities, breakfast and shower/toilet. Food per day can range from 8 EUR to no limit depending on your requirements and your drinking habits :-)
Fuel is around 1.1 EUR/liter but is more expensive in Italy. Switzerland has the best fuel prices form the above countries. Note that motorways are free in Germany. In France and Italy there are toll gates and the prices are quite high. In Switzerland you buy a yearly ticket (40 CHF) while in Austria you can buy a sticker for 4 days, 10 days a month or a year. Goes from 4 EUR for a bike.
Note that we'll be in Mugena (Switzerland) from the 14th to the 24th with a couple of mates riding around the Alpes. In case you can make it on the 23rd I reckon you can meet up with us.
In case you want detailed info on the best routes and tips of all kind I recommend "Motorcycle Journeys Through the Alpes and More" by John Hermann.
I hope that is useful to u and it did not come too late...
Wish you a good ride and nice weather!