Tried to add a couple of lines to the auction description, no other changes. Dutch auction, start price, no reserve, no fixed price. On submitting the changes I get:
The BuyNow price of an auction is the price at which you have agreed to sell if a buyer wishes to meet your price before any bids have been made. Your BuyNow price MUST be above your starting and reserve price. If a normal bid is made then the BuyNow option will disappear.
There is no buy now and nothing on the prices has been altered.