Another vote for SSD. If nothing else, DCS often has some VERY long load times, especially after an update is run, so an SSD is a huge help here. As other have said, bench mark using the free version first.

Also, as a hornet owner, I'd say it's a must have (even in it's current state) if you're a huge fan of the aircraft and naval aviation in general. There's still a lot of stuff coming, but enough to keep one busy (even just learning the finer points of carrier based aviation), and basic A2A and A2G operations. I'll simply say that I'm having fun with it, and feel my money is well spent.