Well if you have a tight budget, really any peripherals will do but here are some options keeping the total under ~$100
(I'm assuming that these are for gaming)
Keyboards
if you want something a bit nicer like a mechanical keyboardthen I would reccomend This one:
https://www.amazon.com/gp/product/B014SHAGVI?ie=UTF8&linkCode=as2&camp=1634&creative=6738&tag=gkb-top-2015-20&creativeASIN=B014SHAGVI
if you are fine with membrane/scissor switch this is cheaper option (although I am not a fan of the red stripe):
https://www.amazon.com/Redragon-Karura-Keyboard-Switchable-Backlight/dp/B00LSGKEC4
Mouse
I am a fan of the lower end logitech gaming mice like the g300s:https://www.amazon.com/Logitech-G300s-Optical-Gaming-910-004360/dp/B00RH6R7C4/ref=sr_1_1?s=pc&ie=UTF8&qid=1471032992&sr=1-1&keywords=g300
And the g303:https://www.amazon.com/Logitech-Daedalus-Prime-Gaming-Mouse/dp/B00OHJY7C2/ref=sr_1_5?s=pc&ie=UTF8&qid=1471032992&sr=1-5&keywords=g300
Headphones
The HD668's are pretty good at a fairly low price:
https://www.amazon.com/gp/product/B003JOETX8/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B003JOETX8&linkCode=as2&tag=biip_081815_over-ear-headphone-guide-20&linkId=BUUY5GCZRE32VICZ
If you want a mic then something like the HyperX clouds will be good, although they are a bit over budget (I used these as my daily driver for years, they are built like a tank and have decent sound quality for the money): https://www.amazon.com/dp/B00JJNQG98/?tag=amazon0e56-20