Tracy, First thing: if your roof/attic structure is truss this does NOT necessarily mean you can simply tear out this wall. Trusses are engineered with specific load-bearing points, and if this wall has another wall or a beam and steel posts directly below it in the basement, it's likely the trusses would have utilized this point for bearing.
There are, in most cases, ways to do what you would like, but you'll want a structural engineer to advise you on if and how it can be accomplished.
Your simplest, most reasonably possible, and least costly treatment here would be to leave the stair and use columns and rails to open the area, but even doing this you may find that wiring, ductwork, plumbing, etc. would need to be moved.
If the alteration on this area will make or break the purchase for you, have an engineer look it over now, before you buy.