Hello,
There are a fair number of Tripods within your budget range, the best one I can recommend for your Nikon D7100 is from Manfrotto.
The tripod I am talking about is Manfrotto 190CXPRO4. It is a three legged (tripod duh 😛 ) and light in weight because it has Carbon Fiber frame.
Both of the above factors will help increase stability.
The weight if you are wondering is around 4 pounds and the size is fairly small.
The price is around $232 if you remove the gear pack. Which is slightly lower than your budget. 😉
You can check it out on Amazon here : Manfrotto 190CXPRO4
Hope it helps. 🙂