Don’t just doubt. Learn!

The difference between art and antiques is that in antique just like prints, there are multiples in the market and just because you found a twin in one grand catalogue does not mean the one in your hand is of equal value for the fact that certain provenance is indisputable especially when it comes from the largesse of a very reputable dealer who is larger than life as compared to that department in a reputable auction house which sends their staffs to learn from him even. And that also brings about the question of authenticity. Could yours be a fake?
In the open, there are keen souls with varied expertise sharing a common passion and hobby. They are not there to help others not in the know but to share their knowledge and numerous occasions, be doubted upon. It’s just that.
You can believe their opinions and comments in entirety or you do not need to. That is purely your choice. But you do not hold one person’s opinion at ransom just because they are willing to help for as far as their own knowledge could stretch. For free and willingness to help. You posted your property in to invite opinions. And not charged a single cent. Thus, It is very unbecoming to want help but doubt the person who offered. If you want a definite answer, go do your own research and reading. If possible, pay an appraiser to tell you the worth of your item. It is USD150 per hour and a minimum of thirty hours for each item you wanted appraised.
And you need solid proofs and investigation to claim a certain expert in a reputable auction house deceived you. They have a reputation to protect. Perhaps you bought your property from a dealer who is well known for selling dubious items? Or that you claim to have inherited it from your father in one of his trips to Japan but investigation shows he has never been there before? Or you may have gotten yours from a shop that doesn’t exist during the time you purchased it?
Even if your property is distinctly similar to the one in the catalogue, prices varies due to its condition, and provenance. A clear provenance ensures that your item is not illegally harvested from a licensed sinking ship. And similarity in rare items calls for appraising and authentication fees which are not cheap.
All reputed Auction houses do not like to face consequences of lot withdrawals due to claims that the property you consigned are stolen goods. So provenance needs to be clean. Proofs to support your claim are as important as authenticity.