DVC discount DTD Basin and GF Basin White

[tb1972]

I've been meaning to post this question after my last trip in early Nov. but time got away. I noticed when I bought at Basin DTD my DVC discount was 10% and when I bought at GF Basin White my DVC discount was 20%. I bought several xmas gifts and things for myself (I tend to stock up!). Did the Basin White cashier screw up by giving me 20% discount or is that the norm?

TIA
Tabatha