To calculate your answer do what resellers do to workout their prices:
What most want is the best for the least which will always be a balancing act:
Do a checklist for yourself about your needs/wants. E.g. If you need/want a strap, if it has to be less than 40 y o etc. Also write down what you wouldn't consider even if all other specs were met e.g. deep scratch, missing cadena and/or cloche etc
The market is what it is now:
Do a global comparison table with other bags for sale and sold (less than a year ago) with the same specs that align to your checklist.
Trace back to the original agent/seller:
Follow images to the original listings so you're not paying commission to extra middle-sellers (like FF or 1st Dibbs)
Add extras:
+ Calculate variables like import duties, other taxes etc, 3rd-party authentication services, spa/repair if need be etc