Reseller value - around $800.
End user value - This is a great domain, and there are many players in the medical records industry, but they are almost all for-profit and would not have much use for a .org. The one organization I know of that this would be a good fit for is OpenMRS (
www.openmrs.org). I've worked with these guys in the past, and I know that the quality or genericness of their domain thing is about 1000th on their long list of things to care about. They're a non-profit organization, and certainly wouldn't give you much more than the reseller value above (and probably not that). They'd rather spend the money on actually doing their core mission. I think you'll find many non profit organizations in this field think the same way.
That said, if you did find an interested party, I wouldn't take less than $X,XXX. As you said, online medical records will only become more common.