Two Christmases ago, I gave my mother a monogram pendant necklace like one that was once worn, apparently, by Christina Aguilera. Ever since, promotional emails from the “celebrity must-haves” shop that sold it to me have occasionally showed up in my inbox.

My laziness in unsubscribing that email list finally paid off on Monday.

The t-shirt that Beyoncé is wearing in the above photo (which was taken at LAX airport about a week ago) is the hot item that these celebrity shops are now selling.  It is indeed a nice-looking t-shirt with short, slightly oversized roll-up sleeves and a print by Public Library. But what struck us is that a portion of the proceeds go to benefit a charity that is trying to build wells in Kenya called the Samburu Project.

Seeing as tons of Beyoncé fans are now presumably buying this shirt, we had to know: What portion of the proceeds?

In trying to find out, we learned a valuable lesson about how inflated the prices are on these websites. Of the three sites selling the shirt other than Public Library, only one of them matched the original price of $38. The “Samburu Hope” shirt goes for $45 here and $48 here — a full ten-dollar tax!

We had to contact Public Library to find out how much of the proceeds are actually going to Kenya. The answer is only 12 percent.

It’s certainly better than nothing, but even Gucci is giving 25 percent of the retail price from that Rihanna “Tattoo Hearts” collection to UNICEF.

Also weird: Check out the Samburu Project’s website. It hasn’t been updated since August, when the Project had nearly reached its first goal of drilling 25 wells in Kenya. Will the Beyoncé boost go toward a new website?