Am I doing this wrong?

Hi. So I read the posts here but this is the first time calling in... I mean making a post.

I only get Audible whenever there is a discount and right now it is three months for 99 cents each month. I rarely get books i know, though when I first discovered audible I used my tokens on things I already liked. Now, however, i usually use my tokens on box sets that are 100+ hours to get what i think is the best value. I do this with Kindle as well, getting the largest book sets i can find. I usually like things in the sci-fi and fantasy genres and have found quite a few good stories.

Basically though, I was wondering what others thought about doing it this way and if anyone uses this strategy.

Also, if anyone had suggestions on long series available for one credit I'd really like to hear them. Currently I'm listening to Dragon Wars 20 book collection which is a little over 120 hours.

Thanks all!