I'd say that isn't enough. Don't buy it unless you honestly believe that your life will be better for having bought it. Take the time and really think about it before making a purchase. You'll be shocked how much useless impulse buying the average person does.
Personally, it's so difficult for me to find out how to calculate value. I'm sure ultimately there is some formula thats perfect for me, but who the hell knows what it is. For instance--I've basically stopped touching my PS4, but this new game came out 2 weeks ago which I wanted to play. I figured, I'll probably get bored of it in under a week, but I bought it anyway. And of course, as predicted, I was bored within 1 week and haven't touched it.
Granted, I got probably like 10-15 hours of gameplay out of it, but there went $60 + tax. Is the $4-6 an hour to play it worth it to me? I honestly have absolutely no idea. During the game, I had fun and lost track of time, but I didn't better myself or anything, and mindlessly passed time. I guess the philosophical debate of what is worth doing is left to another conversation..
I have found that Dave Ramsy is has really good advise if you are in debt, need to get out, and have no idea how to do it. I think it isn't very good advise if you are getting out of college and make 6 figures.