sometimes people also throw in additional artwork if the price reaches a certain threshold to sweeten the deal and encourage higher payment! but take all of this with a grain of salt, I don't do bidding personally so this is just what I've observed 4/4

than the AB. there's also usually a deadline, where once you've reached it, the highest bidder gets the design. if they don't respond within an appropriate period of time (24 hours to like 2 or 3 days but 24 is typical), you do the second highest bidder. if they don't respond, 3rd highest, etc 3/4

the more popular you are as an artist/the more your designs typically go for, the higher the amount you can charge for the AB. it's a tradeoff- you can gamble and do the AB to secure it immediately and potentially save money, OR you can do bidding, in which case the price might end up higher 3/4

Usually (at least from what I've seen on toyhouse), you start off with a starting bid. then you have a minimum increase the bidders have to go up by. then typically you also have a auto buy number for those who want the design immediately and don't wanna sit through the bidding process 1/4