
Hi,
The story about letting her have a litter of pups first is total and utter nonsense. You would be wise to let her have a season first, and have her spayed about 3 months afterwards. Good luck.
:)
Edit: I don't know where in Europe you are, and vet prices will vary tremendously country to country, but in the South of England a large bitch spay is quoted as about £130 - that must be about 175 Euros.