Cutting neighbor's encroaching tree roots

I looked at a house yesterday that seemed pretty good. The only obvious big problem was the grading near the garage. The land slopes just slightly toward the foundation at this end of the house, and I think this is caused mainly by the buildup of soil that's anchored in place by the neighbor's tree roots. The roots encroach to within 1 foot of the foundation at the corner of the house. I imagine that if I buy this house, I'd need to hire an arborist to cut the roots without killing the tree, and then re-grade and install a root barrier. Has anyone dealt with this sort of a mess before? Is it a big deal?