First of all welcome to this forum.
You want this CV boot to be replaced ASAP before the CV joint get damaged by lack of grease and that would cost you even more. CV joints are lubricated by grease. The CV boots protect the CV joints and hold the grease. When a CV boot is cracked the grease will spill out and the CV joint will eventually get damaged. There is a lot of work involved in changing the CV boot as a lot of part (tie rod, control arm, drive shaft) need to be disassembled. Not sure what type of warranty you got but I am very surprised it does not cover CV boots. Does it say explicitly somewhere in the warranty terms and conditions that CV boots are not covered?