Cubase+SpectraLayers or Nuendo - General Music Composition and Game Sound Effects

I’ve gotten back into music composition recently, and I’m looking to upgrade my copy of Cubase 7.5 to a more modern version. With the current cyber weeks sale going on, I figured this would be the perfect time, given that my max budget is about $300. Given that I plan on doing audio work for games as well, I would like to create sound effects for the games too.

With that in mind, I’ve been looking at Nuendo as well. The WWise integration and frequency modification tools that come with it seem pretty good. However, if I just want to do sound effects for a general engine that isn’t directly integrated with Cubase (such as WWise), I’m wondering if it would still be worth it to pay extra to upgrade to Nuendo. I see that there is also SpectraLayers, which allows for directly editing waveforms/spectrograms/etc. Given I plan on doing music production/sound effects, I’m wondering if it would be better in my use case to just stick with Cubase and add SpectraLayers Essentials to it for general audio mastering/sound design, saving money in the process. Or should I upgrade to Nuendo anyway, keeping in mind that I don’t have any immediate need for any of its video synchronization features, and future upgrades would be costlier than Cubase’s upgrades. Otherwise, is there a better set of programs for my specific needs? Thanks!