which wishbone bush is it. the bushes themselves arent that expensive at all. i think even the powerflex poly bushes are only around £15.
you also have the option of fitting bushes with increased castor(superpro) for better handling, or even whiteline anti lift kit. both will improve the handling.
labour wise, im not to sure. fitting the whiteline anti lift kit is about an hours labour. but there is no pressing involved as its already in the mount. cant imagine it being much more time though if they have a hydraulic press in the workshop