I am building a website with a very specific way they want items bid on. That would be the initial bid will always be $125 and each additional bid will increase by exactly $25. So $125, $150, $175, etc.
What would be the best way to do this?
I would probably create like a Bid model that kept track of these. Since you don't want to charge until the very end of the auction, you'll want to keep track of the bid history and then charge the winner (or runner up in case something falls through, etc).
Then you'd just add validations to check against previous bids for the product and make sure they're $25 more than the last.