Which budget engine?

[nobrob]

I'm looking for a budget engine and found these choices.

Picco @ £80
HoBao @ £100
Novarossi @ £135
RB @ £155

All .21 buggy 3 port with standard glow plug.

I currently have the HoBao, and I don't want to take a step backward, if the Picco is less good then throw that out of the equation.

However, I value durability (spending less money) over performance, so please take into account I can buy two Piccos for the price of the RB.

Which would you recommend?

Thanks