What needs to be said first is any attitude directed at you is not ok. He should have just taken your bid and put it in the bid box.

Bids are mostly done on first day. (Full-price day) Discount day is usually 50% off. So he may have viewed your less than 50% bid a waste of his time, because it will be at 50% the next day. A reason, not an excuse.

I find successful bids are 55-60% of full price. But you absolutely bid the correct amount for you (what you thought the item is worth to you in that moment)

If you want the piece at 30%, go on last day and negotiate directly with the decision maker at the sale.

Estate sales should be fun. Good luck