I tend to avoid buying them. I have one NOID Oncidium which I bought for a few dollars from a throw out shelf at the local garden centre. I only bought it because I wanted to see if Oncs would survive my growing conditions and it was cheap enough to kill without any guilt. In my area, most of the NOID orchids I've seen aren't much cheaper than named plants and often aren't of a 'must have' quality so there's little incentive to buy them. I have accepted NOID Australian terrestrials that were offered to me, mainly because they can be ID'ed relatively easily. Actually, I get even more anal about my terrestrial orchids as I tend to avoid obtaining plants without known provenances. Like Kev, I have a number of undescribed and affinis species but I don't consider them NOIDs (they have an ID, just not a name
).