panel doors

[Mary R.]

How do you talk about interior room doors? There's 2 standard sized (30") on Craigslist I could use, if they're correct. Do doors open "in" or "out"? Standing IN two bedrooms, I reach to the left side to take the knob, and pull the door TO me. The barrels of the hinges are visible on the right.
Standing in the third room, the knob is on the right side of the door and I pull it toward me. Does it make a difference? These panel doors are $35 each. Is that a good buy, or about how much are they new from home depot? Hardware comes with. They look to be in good condition.