I haven't had any actual rudeness, but back when I was younger (and 
broke) I used to frequent Repo Records in Charlotte, NC. The clerk was 
usually a middle-aged guy who usually said something along the lines of 
"It's nice to see people your age buying vinyl," and occasionally 
complimented my selections. Of course, I doubt the shop still exists, 
vinyl having become passé ... even Jim Russell in New Orleans has had to 
start carrying CDs to get by, but they still have plenty of new and used 
vinyl. (However, they're not as kind on the prices as they used to be -- 
they started actually looking them up in the book a couple of years ago!)

However, to be slightly on topic, and vent a bit:

I do occasionally get a clueless girl at Jim Russell Records who will 
take my carefully-chosen LP out of the sleeve to check the label -- 
grasping it like a piece of paper and getting her greasy fingerprints 
all over the groove! >:[

The first time she did this I asked her to hold it like that, she said 
"Huh?" and I further explained "by the label and the outer edge only 
please, not by the groove" and she looked at me like I had just asked 
her for several hundred thousand poached eggs on toast with a side of 
zucchini and mango chutney, so I decided that whenever she's there I 
won't buy any records I don't feel like cleaning when I get home. She 
couldn't be over twenty, but honestly -- grrrrrrrrrr!

-Farrar Hudkins