I'm not sure it makes sense even at the $50 price point for you. You're talking about $1150 of software. If you look at things over 3 years (which I typically do with any computer product - hardware or software), you're looking at spending $1800. Consider the 18-month upgrade path we've seen from adobe and that upgrades cost in the (very broad) neighborhood of 25-40% of the full product and you would spend probably $1500 to keep yourself up to date for 3 years if you bought outright. Another way of looking at it is that, spread out over 3 years, you'd pay a little over $8 a month extra for the subscription model.
On the other hand, that may be worth it to you to have access to a slew of other applications you didn't have previously.