What is your approach to series?

[Liquid Ice]

The fantasy being inclined to big, epic stories, there are very few tales that are told in less than three books. Do you buy books of a yet unfinished series or do you wait until the whole thing is out? And if the complete story has been released, do you first buy one instalment or do you buy whole trilogies?

To be honest I always just look at a book and go "hmm, could be interesting" and buy it. Don't ask if the rest of the series is out or not. I mean if all the books are there then all the better. But I really just grab and read. Though thats not the case with second hand books.

Also I buy one instalment. Never the lot.