Why should a small split in a boot mean a new £100 part, as Fiat only supply the whole wishbone not the boot. OK so you can get an aftermarket wishbone for less than half that, but another option is to repair the boot if you can't find a replacement. I can vouch for this type of repair as it has lasted 3 years on my 928.

A bicycle puncture repair kit has been used, patching both inside and outside of the boot.