I think I put a lot of time and energy into Coach shopping, reading about it, looking for deals, etc. But as Bunny said, it's a hobby. I spend my 90% of my days working on research, going to and/or teaching class, writing abstracts and my dissertation, etc. so I like to be able to use my brain (and shopping abiliities) on something that is fun and gives my brain a break from the school/work train of thought.
Sure I could back off some and put my time and energy towards other things, but for this moment in time Coach is where I prefer to spend my free time. Eventually I'll tire of it (like I do everything else), begin to spend a lot less time and energy towards it, and will move on to something else. Until that time comes though, I'm gonna enjoy myself!