Rescue is not a source for 'cheap' animals.
The only reason to adopt a pet is because you love the animal wholeheartedly, know that you can give him/her the very best home possible, and can make a commitment to care for your pet for the rest of his/her natural life, no matter what happens in your own life.
I hope that I've gotten the wrong end of the stick, that your comment on considering rescue because of breeder prices was simply poorly phrased. If so, I apologise. But volunteering in rescue I see this all the time.
Please do consider adoption - it is the right way to go, so many wonderful pets are waiting for their forever families to come along. But please do so for the right reasons - love of the animal.
Wishing you and your future feline friend all the very best.
Cats have amazing personalities and blues are no exception. And I think the best way to choose a cat/kitten is to go to a shelter (or breeder) and spend some time. You will find that, really, the breed doesn't matter. The temperament of the specific kitten/cat matters... You have to find one that fits your personality--it is one of the only times we get to choose "our new baby". And since all kittens are cute, that really won't be a concern once you are in the situation.
Here is a link (only in German) to some blues born in Aug. in Switzerland...probably adopted already, but what you were asking for in your original post. Good luck in finding your new addition to your family.
In that case, I suggest you consider getting an older cat rather than a kitten. Unless you have plenty of things to keep he/she/them occupied while you’re away you may come home to shredded socks, broken items, etc. An older cat will have gone through much of its playful stage and be more inclined to leave breakables alone.
Also I think you’ll find that most of the refuges these days suggest getting two kittens to keep each other company so you could have twice the problems. It’s not a hard and fast rule, but something they’d prefer if you could.
The best thing to do is have a look at the animal-sans-foyer.ch website which covers all cantons in Switzerland. This will give you an idea of what cats are available, their pros and cons, etc. which will help you make an informed choice. If you find a cat/s you’re interested in then contact the appropriate refuge and take it from there.