Anyone ever heard of International Auction Galleries (IAG) in Australia

I have been messaging someone about a coin they had listed on Ebay and pulled off Ebay right after I started watching it and then they consigned to IAG. They refuse to pull the lot from IAG and sell it to me for the previous price they were asking for the coin before they pulled it. The dealer wants me to bid on the coin through IAG, but I have never heard of them before and am hesitant to give my information to an auction gallery I have never heard of before, half way across the world. Has anyone on here ever had any experience bidding through this auction gallery, and if so I would appreciate some feedback. Thanks!