We are refunding 99% of order creation fee if it is canceled. So the cost to create/cancel is very small (just enough to prevent spam).
The end result is that the "order creation fee" becomes a "minimum fee" for filled orders which has the effect of preventing dust orders.
The minimum order fee will probably be similar to a transfer fee, $0.20 per filled order, $0.05 for lifetime members.
@bytemaster Why charge a % fee on the maker just to maybe refund that if he cancels the order, when you can just charge all on the taker. Is the taker that pays the fee anyway by agreeing with the price + fee of the book, think about it.
Also I'm with clayop on fees, today I was showing the system to a friend of my and he asked about the high fee, we need to a least find some middle term acceptable, I think our main niche on short time are going to be exchange anyways, just look at centralized ones, They try to not charge much money on the in out process but only the actual match of order, but then charge high. I totally agree with this approach, is the exchange of goods that create most value for the parts, not transference.