Just purchased a used unit.

\015 I just purchased a used Kirby G4 at a yard sale for $71.00 It has the manual and the shampooer attachment. It seems to be in good shape. I’ve never owned one of these units before and I really don’t know anything about them. Here are my questions:..1. Did I get a good price?..2. What would be considered “regular” maintenance on these units?..3. Are there any “Normal Problems” that I should be aware of?..4. Any advice for a new used Kerby G4 owner?\015 – Kirby G4 Bagged Upright Vacuum