i would suggest a price from Powerhouse (luxy & Bumper) for a Vertex, Prox or Wiseco, i hate to say this but the OEM Honda pistons are shit so i would go for aftermarket.
i have purchased a Vertex for Emma's bikes big brother but it looks like a cast piston to me (cost for piston kit was $180 at Dandy Honda, they also quoted $280 for Wiseco) i have run wiseco's in my CR's for 20 years and allways was happy, time will tell on the Vertex, the guys on the forum reckon they are the goods and for me it was $100 that stayed in my pocket. the Wiseco pistons are definately a forged unit.