Dont play with the "I know where you got them shoes" guy.

I've been there plenty of times and the last time I was there I had 3 different guys on 3 different streets ask me that same thing. I was dressed in jeans and a t shirt once, dress pants and a collared shirt the next, and full out Saints gear the third. I was blown away by this statement and for the life of me, I can't figure out what the hook is. I even asked around with the local bartenders and waiters and no one gave me a straight answer.
Can someone please tell me how this ends?
Are they trying to bait you into saying your from out of town?
Trying to get a buck off you?
Trying to sell you drugs?

By NO means did I look like I was from out of town, I looked like a total local. WTF?
I'm still perplexed about this one!

Here ya go...if ur say on Bourbon st and they come up and ask.."Say i bet can tell you were you got your shoes for 10$"..and you being the tourist want to see if this guy is psychic you say.." Ok tell me where" he looks at you and says "Bourbon St...now give me my ten dollars" get it?

Another answer you'll maybe get is "on your feet". Saw that in a NOLA commercial a few years back, when I still lived in the area.