the other thing that can happen is you jump buy the first train you see for a high price and decide to buy it now. A few minutes or hours later you see the same engine or item for a cheaper price, it's all good and stay calm it's just the way hobbies are now you see it now you don't ! also if you are buying a used engine MAKE SURE YOU TESET IT ON THE test track tables so you don't get burnt
Alan