speaking as someone who owns a bike shop in Morzine, AND takes my own away when I go on holiday – I can see both sides to the argument.
All depends on you, your bike, and your bike maintenance skills.
We cover all wear and tear on our hire bikes and buy them new each year. What you’re paying for is peace of mind that if anything does go wrong with the bike due to simply riding it, we take care of it – if you blow the shock or forks, we fix that. If you snap a spoke, or buckle a wheel slightly, we fix that. Snapped gear cable, brake bleed, brake pads, tyres, etc etc. All stuff that your €80/day will buy you. Any crash damage is charged at less than retail.
Plus there’s no hassle packing / unpacking the bike each end.
The other thing is the type of bike you have – is it suitable for alpine riding? would you have more fun on a bike that’s set up for alpine riding? Are you just going to hammer your trail bike down the DH tracks? (If that’s what you’ve got!)
And the last argument is flexibility – it’s a whole lot easier to choose to hire a DH bike for a day or two if you want to have a blast on one if you’re renting anyway! Or vice versa – hire a trail bike to get away from the lifts for a day if your main thing is DH.
For a 4 day trip I’d say it’s worth renting.
And why wouldn’t you hire? Well because you bought an expensive bike and you want to ride it in the alps!
I fly and travel with my bikes all the time – never had an issue on the flights etc and am happy to fix it when it breaks.