Implement Dynamic Bid Increments and Seller Minimum Price for Auctions

Context

Your PubNub auction platform needs two pricing features:

1. Scaled bid steps: At low price points, small bid increases are acceptable. But as the price rises into the thousands, allowing $1 increases wastes everyone's time. The platform needs price-dependent rules that scale appropriately from low-value to high-value items.

2. Seller protection: Sellers want to set a minimum acceptable sale price. This price must remain confidential -- bidders should only know whether the threshold has been reached, not what the threshold is. The auction end logic must also account for whether this threshold was met.

Task

Implement the server-side logic for both features. For bid steps, create a function that determines the appropriate minimum increase based on the current price and integrate it into bid validation. For seller protection, implement the storage, checking, notification, and end-of-auction handling for the confidential minimum price.

Expected Outputs

• A function that returns the appropriate minimum bid increase based on the current auction price
• Integration of the dynamic increase into the PubNub Function bid validation flow
• Server-side storage and checking logic for the confidential seller minimum
• Notification publishing when the seller's threshold is crossed for the first time
• Auction completion logic that accounts for whether the threshold was met