Regardless of what one can technically afford, I do not believe buying things because one can is always the route to go. In theory, I have enough money to buy both games at full price but I also believe in fiscal responsibility. I pick between one game and another every single year. I cannot afford to always buy every $60 that seems as if it may tickle my fancy. I must
really like a game in order to convince myself it'd be a wise purchase, even as an adult.
This year, as more and more information was released regarding NBA 2K14, my number one gaming purchase drifted from 2K on over to GTA V. Contrary to your assertion, I feel there's actually been a fair amount of impressions thus far that have seemed to suggest that while current generation 2K14 has some improvements, it's still almost closer to a big time patch than an out and out new product. I think this may be one of the years where a demo would have been most helpful. Alas, there is no demo. As such, a lot of folks are having to make purchasing conclusions from a distance.
I think it's a reasonable question. I've been thinking about it since I found out GTA's new release date. Previously, 2K has been irresistible to me. This year, I've found GTA's release to be just timely enough to potentially hold me over until 2K14 on the current generation drops in price. As it stands right now, I do not have any real yearning to play the new NBA 2K, which is much different than the feeling I usually have around this time of year. A lot of that has to do with GTA (and 2K14's apparent underwhelming upgrade).