No, I often buy used text books when I find them cheap so I can fill in what I missed by skipping out on a degree.
I have a separate title on discrete math (Epp) but its companion only had some solutions to exercises available in a separate $60 [used] book. I found this title and figured that with the intersection of ML and discrete math I'd have better luck. (Staring at a ton of problems in a text book without knowing which ones I'd be able to verify my solutions against - the Epp book - was a daunting prospect for self-study).
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.115...