I'm sorry, but aren't those two the same thing?
But this is very true regardless. You don't find many complete series in my opinion because it doesn't make the most profit. If you can keep producing and have a captive audience, then you'll definitely get good cash flow. On the flipside, it also makes it more daunting to get into a series where you have to decide to start from the beginning and massively catch up while knowing that the list will expand while you read, or just take your losses and start from something somewhat recent.
On topic, I did enjoy the book. The epilogue didn't bother me, but knowing that it was all planned out made me feel better about it, because I didn't necessarily agree with the pairings and especially not the naming of the kids, but whatever. S'all good.