You can do it cheap, we have prefected it over many years, culminating in a group of us buying an LDV High top and cramming 10 of us in, see here page 54
This year 4 of us went to Bourg (Les Arcs) for 8 days and it worked out pretty cheap. We managed 7 days of riding too as oppose to 4 or 5 with a hol company.
(All Return costs)
Ferry £85
Fuel £290
Tolls £145
Camping £150
Car Insurance for extra drivers £90
Breakdown cover £26
£786/4 = £196.50 each
Extras were
lift passes (70 euro/week for Les Arcs)
Food and drink – Varies depending upon if you go out or not, but noticeably cheaper this year as uk prices have risen and the euro is better for us
We did spend extra going out for meals and beers, had a day guiding from Stevo at the White Rooms, and bought lift passes daily as rode la Thuile twice and planned to go elsewhere too.
You can save on camping if you really want to, we never used to pay for camping but rode somewhere different each day and got that pissed in the van we didnt care where we ended up sleeping but im getting too old for that now, ill pay £37 to camp in a camp site for the week and chill thanks.
The fact i blew a grand ona new frame, wheels and forks etc a week before i went is just minor detail (and it 90% recovered now by selling the old stuff – thank god!)