Grado SR60 is a very popular starter headphone (70$), and has an amazing sound, which can be heard without a headphone amp. The alisandor MS1 is called the best headphone under 100$, which is also in the quasi-grado family. You will not be dissipointed with anything that says GRADO on it, and thats what ide recomend for a first headphone (they were my first and ive been slowly moving up the range).
Also, welcome to headfi, sorry bout your wallet