One PSO credit roughly corresponds to US$100 in value. And in fact that's the purchase price of a single credit. Discounts kick in for buying multiple credits. The datasheet for PSO Credits has a table of the discounts. For example, if you buy 180 credits (which is what it'd take to send 6 people to I&C or other VMware Infrastructure courses with the same price), those credits would cost US$90 each.
I don't want to say that 1 credit is equal to US$100, because not every VMware item is purchasable with credits. For example, you can't buy VMware software products with credits.
