You're far more likely to find what you want when you have all of the available information readily available.
You'd laugh if a used motorbike dealer only offered to show you half of his inventory.
Looking for a used Moto Guzzi Nevada 750 you can afford?
Many top motorbikes are available for under $6,800.
If you don't have good answers to that question, you need more information before making a major purchase.