Random person here, but for the headphones, mouse, keyboard, and optical drive, you could of chosen other things. For one, Astros are labelled as "gaming headsets" and have a brand name attached to them. So, it's expensive like Beats, Turtle Beaches, and Trittons are if you're just doing regular gaming, music listening, etc. That said, they're not bad headsets, but there are alternatives. I'd recommend going to headfi or other sites to find a less expensive and similarly effective headset. For one, the Creative Fata1ity could work if you want a really cheap headset. Audio Technica's headphones are great from what I read along with Sonys, Logitechs, and more. They don't have mics, but you could find a decent clip-on or get a decent mic. Also, you'd want to get a sound card if the motherboard's sound doesn't cut it. A good pair of headphones can only do so much with the sound quality of a sound card or onboard sound.
For mice, that one looks fine and they're based on personal preference so nothing there. So, Steelseries, Razer, Logitech, Mionix, and Zowie are among mice companies. The keyboard, well, I wonder if the branding adds to the cost. You could find another mechanical keyboard for less than that. Maybe a Ducky, Cooler Master Quickfire, and others. If you hadn't purchased the optical drive, you could of gone with a Blu-Ray drive or some cheap drive like one of Asus's or LG's.
With your budget, you could get 16GB or 32GB of RAM for the hell of it.