Is Macklemore and Ryan Lewis a headliner? I understand they have (had) the number 1 song in the country but would that many people go and see them?
There's an extremely (undeserved) obsessive mindset in regards to them up here. People eat his shit up in the northwest. He headlined Bumbershoot and filled Key Arena in 2011 so yeah he won't have trouble filling seats.
This lineup is not worth $350. No way in hell. I'd go for most of the hip-hop (Danny Brown, Ab-Soul and Schoolboy Q, POS, Nacho, yadda yadda yadda), Primus, Torche, and a couple others but that's a shitload of money compared to something like Warped or Bumbershoot.