Buying house with Messy Neighbor?

I found a house for sale for a little under $100k. The appraised value is $120k. Similar more updated homes in the area have sold for $160-180k. Needs some renovations (approx 25k) to bring it up to par with the more expensive sold listings. Problem is, the neighbor has a bit of a junkyard going on in his backyard and front yard looks neglected, and some odd exterior work. I was thinking that if I buy this house that I would screen the entire neighbors yard using an Arborvitae type shrub so there is a natural wall between the properties and the tenant won't have to see his mess. The neighbor is also why I suspect this house is still for sale. The neighbor looks older so they may not be there for a long time. How big of a deal is it to have a junkyard neighbor next door to tenants do you think and how much will my rental rates get haircuts due to this?