I’ve been three or four times to that area in the summer and every time i’ve driven. You need to have a couple of drivers if you’re going to drive, i’ve done it on my own a couple of times from Preston and its not a pleasent experiance, last year there was two of us and it was much better! It wasn’t so much the cost of flying/driving it was more the fact that driving is a little more straight forward (for me). You can take as much stuff as you like (within reason), go when you, i feel safer that my bike isn’t getting thrown around want and just don’t have the hassel of flying. Costs wise last year was £300 fuel, £150 for the tunnel (don’t use the ferry they are minging) and about £120 in tolls, that was between four of us from Preston.
Riding wise i’ve never used a guide out there but i think if/when i go next i will try to get some accom that offers guiding, just so i can get to some hidden stuff that is smooooother lol, because the trails out there do get battered, they try their best with cutting the brake bumps out but its an impossible task.
If you want a cheap look at alpine elements, they did a holiday (self drive) for £199 fully catered. We thought the place was alright for a cheap holiday but other people on here thought different.
Anyway hope this helps