Although I have never used the buy it now or nearest offer for coins etc, I do run an
ebay retail business made up of buy it nows and buy it nows with nearest offer.
I have a main account of which I use the above for all of the items listed, I usually have very good prices which sell rapidly, recently I have put all of my prices up by 30% which is a huge increase, this just to give me some time off for the Christmas period, a few items have still sold, about 20% quantity of the normal sales volume, so buy it nows in general do work. Some people will pay excessive but obviously takes longer in general before someone buys.
The buy it now or nearest offer also works well because some people just buy it now at the excessive price, other DO barter up to 3 counter offers each. Some buyers ignore counter offers, I find this about 50% of buyers. Be patient, some people offer a ridiculously low price and ignore the counter offer completely, others are looking to negotiate a price in between. Buyers who respond quickly to counter offers usually really want the item so step down fairly but take the risk of losing the buyer. If the buyer takes a while to re-counter, counter back with your honest best price with a note saying 'this is the very best I can do'
I also have 10 (yes ten) other private accounts of which I only use auctions. I NEVER use 99p start for anything that I would be unhappy to sell for just 99p... it does happen with items. I have had £80 jeans sell for 99p back when I first started.
Every other weekend (near enough), all private accounts get 100 free listings starting at any price over £1. So you can list them starting at the price you want, for example £25, if no one bids, you do not pay anything. If the sell, you pay the usual 10% final fee. This is perfect for me as my 10 private accounts allow me to send 1000 auctions off every two weeks (1-3-5-7-10 day auctions). All items are listed starting at a price I am happy with. Approx 5% of items sell. and about 1 in 3 of these items get bid up further. (sometimes bidding wars cause items to sell for more than you can get them down at the nearest shop)
This may be the best option for you as it is risk free, you can relist every 2 weeks on 10 day auction for example starting at price you want minimum.
Hope some of this helps, I am gaining a lot of experience from this site but don't have much to give... this is probably my best field so I hope it helps, let me know if any questions
Thanks