Thank you both for your input. Based on the details you have provided, I agree that my plant is not Purple Prince. I have put in a request to transfer the photo to the generic Lilium plant, since there is no way now to know what it is. Sadly, my photo matches closely to the photo of the seller (Breck's), so there will be lots of "Purple Prince" plants out there that are not really "Purple Prince."
In any case, I like the plant a lot, especially if it grows and gets more blooms this year. Orienpet Lilies seem to thrive in my gardens.