hey just a thought

depending how long the boot has been ripped the joint could be worn out

just go to autozone or somebody
buy a rebuilt unit and put it in
then return the old one for the core charge
it will take out the guess work on if the joint may be bad

it should be to much more than $100 after the core is added in
on my moms 95 toyota avolon my dad and i slid a new axle in in less than 2 hours (had to get his tools from work) and after everything was said and done only cost around $70