The area is very poor for Fleas. The Walden is the primary one I've heard of. You can always head out to Clarence and check the antique marts out there. I find they can be a bit over-priced, but if you are willing to look, you should be able to find a bargain or two. Keep an eye out for church garage sales -- St. John's Grace (the Episcopal church at Bidwell Circle) always has had a good one. I just can't remember when it's held.
I do wonder if there is anything worthwhile over the border in Fort Erie. I haven't checked that! There might be more action up Toronto way as well.
But... Buffalo is pretty lame as far as Flea Markets go. If I hear of any, I will certainly let you know!
Thriftily,
Alexandra
www.livingwithoutmoney.blogspot.com