So tomorrow i will be going to purchase a set of Bilsteins i believe it is the HD series second hand with around 30k miles on them. They have been used with the stock springs, and a member of Static Nine Garage informed me that they are good shocks that last longer than OEM. But my question is what signs should i look for before making the final decision? And before some o f you say to buy new ones, I am a college student living on a budget so paying close to $500 for a new set is a little out of my ways as opposed to $200.