
Firstly, I agree with everyone else - wait!
Secondly - avoid getting any puppy you have just seen somewhere, especially a collie. Collies are so often victims of bad breeding, whether it be intentional to make money or because the parents are so pretty and so nice and the owners just wanted them to have a litter... either way it can go spectacularly wrong because they can end up nothing short of neurotic! My older collie is a prime example of this - naturally she is incredibly nervous, noise phobic and bigtime reactive. She was raised by idiots so is nothing short of a headcase now (although vastly improved since she arrived 21 months ago) but, her sister (possibly half-sister) was raised by sensible people who got help early, and she still shows all the same issues, just to a much lesser degree. So very much a case of bad breeding, and an intentional one. It wasn't a one-off bad litter either - there are 3 years between these two girls.
My younger is also naturally very nervous and again was bought after the owner saw her advertised - accidental breeding in her case (through negligence/idiocy) - but that background has made her an immensely challenging dog, so she ended up here at just 11 weeks.
If you are really set on another collie, then I really would wait until your youngster is a bit older, and find yourself a good breeder :-)