it does not have to be expensive as long as it is made from quality steel so it does not flex. I have quite cheap one but its steel and works very well
Radek
V4 D8 - RX8, XERUN 4168SD
F1-09 - Tekin RS Pro, 17.5t Redline, 2S LiPo
Sakura Zero S - LRP, Saturn 20T, 2S LiPo
*EX-10 Eurus*