I agree, Audible is sneaky evil.
I had the same plan, join for a year and use credits to get some audiobooks that I can't get from the library. But, the sales!! I can't resist an audiobook for slightly more than a cup of coffee. Two more that I had to have in this latest sale. I refuse to count how many audiobooks I bought last year. Plus there are 30+ audiobooks on my wishlist.
I'm not cutting the cord any time soon.
