Don't know if these are the lowest prices, but Amazon has the Rampage for $33, the Retal (White "Elite XD" version) for $30, Modulus Ghost-ops Chrono barrel for $15 (used to be
Nerf Elite XD Stryfe, Hobbies & Toys, Toys & Games on Carousell
Amazon.com: Nerf Elite 2.0 Echo CS-10 Blaster – 24 Official Nerf Darts, 10-Dart Clip, Removable Stock and Barrel Extension, 4 Tactical Rails : Video Games
Amazon.com: NERF Strongarm N-Strike Elite Toy Blaster with Rotating Barrel, Slam Fire, and 6 Official Elite Darts for Kids, Teens, and Adults (Amazon Exclusive) : Everything Else