Demanding Accessibility from External Suppliers

Both for principled reasons and practical ones, we need to be using and building technologies that make Yale's world accessible to many different sensory/physical interactions. How can we insist on this in an world of limited choices, funds, and time? If the otherwise perfectly suitable application to support an effort is inaccessible to [impairment X], do we not adopt that application? What if the immediate situation has no expected users with [impairment X]? Do we need to wait for the ideal application? Build it? And hey, we're Yale. Isn't there some way to leverage our position (money?) to encourage vendors to incorporate accessibility at the core of their products?