Ask HN: Wrong choice of SaaS vendor, what did it cost?

Are you witnessing wrong vendor deals is SaaS? When closing with a vendor are the people making decision going for business-need, product-market fit or relationship and promise to customize to business needs? In recent meetings with prospect we hear, wrong choice on vendor and budget loss. Either the vendor never launched, or contract was such that they were forced use the vendor. Any insights will be helpful to learn the SaaS landspace better. Some lost their jobs because of the wrong call.