I have been here many times and spend hundreds of dollars in meals with friends. The first time our bill for 3 was over $330. The restaurant is expensive and you should be prepared for that!
I highly suggest you order the causas and the ceviche sampler and the lomo saltado. The Lomo will set you back around 39 dollars if I recall. The meat is filet Mignon, so you are paying for quality.
For a better experience and to keep your cost down, lunch is a much better option. Ask for a table in the patio which is now covered. Overall a very good experience of high end Peruvian but for better Peruvian and a more humble option you should fly to Los Angeles.