If you send her with a bottle of decent rum, I'll take her tea shopping.
A tong of 'nicer sheng bings' for $200-300 is not happening in HK.Tea can be very expensive here--as can wine, Cuban cigars, fine dining and cars. Most expensive of all is property. I'm watching small businesses close up all around me, and chain stores and hotels opening up where they used to be. The rent is killing a lot of older businesses. Tea stores, though, persist. People have to drink tea, and profits must be pretty good. The way this neighborhood is changing, you can find Starbucks next to traditional Chinese medicine dealers, and pizzerias and sushi bars next to old school tea hongs.
Now, that being said, there is decent tea to be had, but $200-300 a cake makes a lot more sense if you want something halfway decent. Prices for sheng here are significantly higher than in China. $50-60 will get you a decent cake of drinking shu. I live here, and I buy a fair amount of tea online from China, just because it's cheaper and easier. I do buy oolongs from local dealers though. I tend to like oolong a lot more than pu erh nowadays!
Now, if I just want a bag of loose shu pu erh to drink, I'd probably buy within 10 minutes of here, just because it's easier.