Yamaha HS50s
 

Someone recommended that I buy Yamaha HS50s recently.

Being a noob, I don't really know what I'm getting myself into, so would love some tips before I buy anything... Are these good bang for buck? I've found a pair online for $500. I don't know if it is necessary information but I use logic 9, and a macbook pro (old one now, but I have very little trouble when recording)

Secondly, how much would I be looking at for an amp to go with these speakers? I've had a lot of practice with recording software but have always used headphones or just an ipod dock for playback, and am finding myself more and more frustrated when I play my tracks on different systems.

Thanks!