PC Pleb needs your help

Trying to build a PC, and I need help from someone who knows something about computers. I found a deal on craigslist and the guy is selling:

- I5-3570K processor with stock cooler
- ASROCK H61M/US3S MicroATX Motherboard
- Corsair 8GB DDR3 RAM

He is asking 150 - but I talked him down to 120. Is this a good deal? I am just looking for something starting out that I could pair with a nice graphics card and have a mid-tier gaming PC.

Thanks!