I can’t believe it’s worth the hassle/expense if you intend driving it to Europe on holiday.
Touring holidays are great. A tent would be a ballache for touring, and motorhomes – well they are insanely expensive.
A European caravan trip isn’t much different to a motorhome one except that you might lose the ability to stay in car parks. On the other hand you gain the ability to do easy day trips without packing up.
Costs about £450 on the train at peak times as opposed to what, £200 in a car. The extra fuel cost is probablyu another £150 to the south of France. But that’s similar to a motorhome I’d guess.