Can't seen to find a 5-blade head for the T-rex 250 clone for a cheap price. I bought a flybarless head for it instead ($40) and I bought the KDS Flymentor 3D Auto Stabilizer system for it. Hope it's small enough for a 250!
Looks like if you want a pocket size 5-blade MD500 for cheap you got to go 450.
http://www.hobbyking.com/hobbyking/s...dProduct=12612
250 Head
http://www.rcmachine.net/scale-cnc-5...lb7ukllin7gtt0
Hard to pay $140 for the 250 one when I see the 450 size for $25