What is a good low cost antenna design for a low cost 433 MHz transceiver?
You cannot ask for good unless you define what is good for gain in each direction of XYZ.  

Define it just like an illumination design with intensity needed to have error free reading in defined directions. 

This is a space diversity tradeoff with gain and omnidirectional 0dBi only exists on paper.

If you cannot define priorities for the design; cost range, performance range, size range; so that suitable tradeoffs can be made to meet all 3 , then the solution cannot be defined.  If they are realist and can be defined then meeting the spec makes it perfect.