What company makes the best low budget crane for under $400.00?

Cobracrane, Promax, NUangle?

Which one has performed the best?

I am using a DVX100, I would need to support it.

The low-end Cobracranes are too flexible for that class of camera.

I say that because the beam twists and the brackets flex. And as you raise and lower the boom, the twist changes because of the changing strains on the beam. And the brackets flex more or less, mainly the beam to tripod bracket, as you move the beam because the load changes.

Then when the wind kicks up, the whole thing does an interesting oscillation.

I have one with the extension kit and think it is marginally OK for my PC110 and unacceptable for my PD150 unless I am inside and moving things slowly if at all.