On stockx when u ask that's the asking price the seller wants to sell their product at. If you're a seller you can accept any bid or buying prices that any buyers are willing to pay. Or you can ask for more money, which is to increase your asking price. If a buyer will buy or accept your asking price then you have to mail out your item within 2 shipping days to stockx HQ, and you can print out a prepaid UPS shipping label they give you. You have to ship within 2 days or pay a percentage penalty for mailing late
You also have to include a piece of paper from stockx that says this paper must be included with your item for authentication, this paper can be printed out with your shipping label, all the details are emailed to you.
If all's good and your item passes authentication then you can receive PayPal payment asap. Recently iirc now you can receive instant payment and wait for your product to pass authentication. If there's issues they will send back your item to you and you have to return payment.
When you bid, it's a bid you are placing to buy the product.
There may be multiple bids from buyers who want to buy the product, and it's up to the seller to accept which bid they want to sell their item at. They can accept a lower amount, asking amount, or higher amount. It's sort of similar to eBay but here you can place bids 1 at a time instead of quick multiple bidding on a live auction. Its a bidding competition between buyers.
Or you can accept the sellers asking price and buy the item at the price they want.
After that then you pay for the item and shipping, then wait for seller to ship item to stockx for authentication, and then you get it.