Here's how it works:
* The seller sets a price but is open to lower offers. They may be willing to accept a lower price if it's a good offer for them.
* Buyers can make offers below the asking price. This gives buyers the opportunity to get a good deal.
* The seller can accept, reject, or counter-offer. The seller decides whether the offer is acceptable or if they want to propose a different price.
Essentially, "OBO" indicates that the price is negotiable. It's common practice in the horse buying world and allows for flexibility in pricing.