I dont work for Vueling, I work for Air Europa. However I have lots of friends at VY.
With hotel, food, transport, etc your TR will indeed cost you 25000 euros and of course they will not pay you. You will be treated like everybody else, sumer contact with a low basic wage and then you will have to look for another income source during winter as they will say "adeu". Yes they are looking for alot of pilots but in winter they don't need them at all.
There are a lot of people with experience looking for those jobs, dont think that you are alone!! I have 2 friends on B777 emirates, one is captain, and they both would take a fo job at ryanair if they get the base of their choice.
If you are from germany i would rather apply to germanwings or eurowings, they are looking for pilots and the deal is better.
Good luck.