There are cheaper brands of reeds out there, but I won't run anything but V Force...its all personal opinion though.
Best price I've seen on reeds are these on Ebay: http://cgi.ebay.com/ebaymotors/Banshee-V-Force-3-Reeds-Cages-VForce-Yamaha-YFZ-350-/330540820922?pt=Motors_ATV_Parts_Accessories&hash=item4cf5c4a9ba#ht_636wt_933
Yeah timing plate is a well $40-50 spent. I run a Ricky Stator timing plate, but the Chariot plates are really nice as well.