Show HN: BidWix – I built a sealed-bid tool where honesty is your best move

Hi HN — I'm Stéphane, the maker of BidWix (and myNoise, if that rings a bell).

I'm a sound designer. For years, I've licensed sounds and music to people whose budgets I couldn't see. You send a quote, close the laptop, and spend the next hour wondering: was that embarrassingly low, or did I just kill the deal? The core problem is simple: when there's no market price — think a logo, a photo license, a domain name — neither side wants to go first. So both bluff, both guess, and the final price often has nothing to do with what would have been fair.

BidWix fixes this with a sealed-bid mechanism. Both sides submit their honest number in secret. If there's overlap, the deal price is the geometric mean of the two — the point where both sides gain by the same proportional factor. If there's no overlap, no deal, no hard feelings.

If the seller's floor is $100 and the buyer's ceiling is $900, the geometric mean gives $300: both sides gained by a factor of 3.

The mechanism is also incentive-compatible: since you only get one shot and never see the other side's number, your best move is to submit your true boundary. Bluffing can only cost you the deal.

It's free, no account needed, and intentionally minimal. Happy to discuss the game theory, the geometric mean choice, or anything else.