BP morphs are still expensive enough that even the hets and often possible hets will still cost more than a normal.
Corn snakes on the other hand, have had so many morphs for so long that some breeders don't bother to keep track of which snakes might be het for the more common morphs. So you might buy a "normal" that is actually het for something, but then you have the problem you don't know if it is het, or het for what.
Getting back to BPs, if you think it is likely you will want to breed in the future, I'd recommend starting out with a female, as they take longer to reach an appropriate breeding size. If you can afford a female het for something you like, go ahead. Otherwise, you can still get morph offspring in your first breeding by going with one of the dom or co-dom morphs.
Which brings me to another point... there is no such thing as "het for pastel" because pastel is a co-dom morph. That means if the snake carries the genetics for it, you can see a visible expression of the gene. If a snake carries 1 pastel gene, you get a regular pastel. If it carries 2, you get a super pastel, which is even brighter than a regular pastel.