Unless it's major, or the lens is dirt cheap and has other issues that would make it worth taking apart, I wouldn't bother. Fungus doesn't really do any harm to your images. Plus if it i quite bad, then the chances are it can;t be removed without damaging the coating anyway, so you're paying for nothing in the end.
*I have fungus in a lot of lenses, I usually seek out cheap lenses because of fungus, and I;ve had several opportunities to compare fungussed and mint versions of the same lens, in all cases I've kept the fungus ridden lens and sold the mint one.