Going to Avalon always seems like a really great idea until I actually go. Don't get me wrong, this is hip and you can find some pretty cool stuff occasionally, but for me it's really hit or miss. Sometimes I have a really hard time understanding how they price their items. Once I picked our a tshirt that had holes in it and it was $14. As far as "thrift stores" go, I wouldn't exactly say its super thrifty, but I have gotten a few items priced lower than they would have originally been stores (AE jeans, Urban Outfitter top).
Another thing I don't understand is how their buying process works. I've taken clothes here a few times to sell...and that process is also hit or miss. I've taken almost new, "in-style" clothes there and they didn't take anything, but then you look on the racks and they have clothes that look like they should belong to someone's Grandma.
In conclusion, shopping here is definitely always a mixed bag, however any time I'm in Squirrel Hill I make sure I stop in just to see what they have. They also always have a very good selection of Halloween costumes in October.