I have a form that receives bids for items. It is shown below:
In green you can see the price for the current winner bid, below, the minimum increase for the next bid (in the case of the image, the next bid must be $ 2510) and below the button to make a new bid. Next to this button (to its left) there is an input so that the user can enter the desired value to bid, since the bid may be higher than the current winner bid + increment.
My question is: Which is better from the standpoint of usability? It's better to have the input always default to the current bid value + increase and if the user wants to make a higher bid he changes the value? Or it's better that the input remains empty and the user makes the bid only pressing the green bid button to make the default next bid and enter the value in the field only if he wants a custom value?