My success rates are higher, but it's because buying at auction is for getting rare coins I won't otherwise easily find. I'd prefer to buy more common coins from dealers and skip the commissions. If I am placing advanced bids I typically bid heavy to ensure a good outcome. I dislike this style of bidding, since I fear I might end up winning at my max due to auction house shenanigans. I will do this only when live bidding is not available. If I am bidding live, it's typically taking me away from my job, since European auctions are typically during the morning, so for me to be bidding live I am quite inclined to bid to win. I am not looking for bargains. I'd say my auction win percentage is 30-40% (not including "placer" bids on eBay just to watch an item)
Some auction houses still offer this. Gorny & Mosch, for instance (or was it Kunker, or both? I can't remember ) lets you set a maximum expenditure for the session. Of course, you are also limited by your pre-determined credit limit with the auction house. I've never pushed mine to the limit so don't know how well it works in real time. Plus, I usually bid live rather than ahead of time.
Maybe 20% for high end stuff, close to 50% for common stuff. I set my max bids to be lower than vcoins retail, taking into account the ridiculous anachronistic "buyers fees" (what exactly am I paying an extra 15-20% for???!!!). It's a very unpredictable market - you get a bargain sometimes. Other times the coins hammer at well above what I'd consider a reasonable price. I think it's an indication that there's relatively few customers in the market. You'd expect consistent prices, like I see with houses, if there were lots of people participating.
Why do you think buyers' fees are anachronistic? They used to charge seller fees only. Buyers' fees are the new idea. In the coin-world a lot of auctioneers are selling their own stock, but usually the auctioneer is acting as agent for the seller. They *seem* more attractive if they offer low or zero seller commission, so over time the seller commission has almost disappeared and the buyer premium has grown. But it shouldn't matter to the buyer. Set your max price and adjust down to allow for the permium. Why should you care how the price is calculated?
I want clarity around the actual price, I guess. Buyers fees, plus whatever the unfavourable currency exchange rate is, plus whatever mystery figure the postage turns out to be, makes the actual price less transparent. You know, in Australia, the shelf price of an item in the supermarket includes taxes and it's exactly what you pay at the counter. You don't need to do any calculation. The seller's problem of pricing structure shouldn't be shifted to the customer. My point is, buyers fees are an irritation, and no value-add to the customer. And unless a business places the customer at the centre of its business model, it will die in the 21st century. There will be new businesses that aren't as irritating to deal with. I'm not sure seller commission has disappeared either. Certainly Roma and CNG still have this. I haven't enquired more widely though.
If you're consigning anything of value you'll be able to negotiation commission of zero *or less*. The most valuable consignments generally get a share of the buyer's premium back. Agree about non-transparent pricing, though. But I see it as a minor irritant. It's a bigger problem at places like Sotheby's and Christie's where tiered premium levels make the calculation quite complicated. Postage is an interesting one, though. If postage is included in the price then people who buy a lot of items end up subsidising people who only buy one, because pricing will assume you're buying one thing. So I'd say pricing is more transparent is postage is separate.