Costs of caucasian and African-American sperm difference?

My partner and I have begun the process of artificial insemination and had our first consultation at the fertility clinic. We got to look at profiles for some of the donors and noticed that the prices for pure caucasian sperm is quite a bit higher than that of African-American, Latino or mixed. I asked the lady why that is and she said frankly it's because there is a higher demand and less stock of Caucasian donors. This doesn't seem right to me... almost seems like it would be illegal to charge more for one type than another. I don't know maybe I'm just thinking into it too much, or maybe I'm just miffed that I have to pay more to have a baby that is the right color.