Many car dealers say that the price of cars in One Price or One click sections are higher comparing to the prices of cars in usual auction. However, as in example below it is not always true.
In video above bidding for the car reached 1,865,000 JPY, but reserved price "urikiri" didn't open, so the car gone unsold.
Later the owner in order to sell his car, requested to upload car to One price (Fixed price) section with the fixed price of 1,800,000 JPY. Thus the selling price in One Price section is lower comparing to that of auction.
"One Price" is just a price the seller would be willing to sell the car for. The car goes through auction and if it doesn't sell they have the option of putting it in "One Price." That should give you an answer as far as condition...it's no different than the auction
To read more about one price or one click cars: https://www.akebono-akb.com/post/auction-one-price-or-one-click-cars-akebono