<human>: I run past a certain house most days (my normal 5k run) of the week.

The house usually has one or more bikes "for sale" in the front yard.  Always children's bikes and/or scooters.  Between one and three vehicles for sale.  Chained to a planter in the middle of the driveway with a "FOR SALE" sign on it, and a price tag.

The weird thing is that the vehicles on sale change every day.  Each time I run past, I see a new set: different tricycles, girl's bikes, boy's bikes, scooters etc. 

I finally had to ask -- pretending to be a potential buyer (well, technically I was a little interested in the mongoose scooter on sale for $18); I knocked and inquired.  He tried selling me the scooter ("This one has very little rust..!").

I told him, I walk by here every day and see many different bikes for sale.  Curiously, where do you get them?

His answer was very non satisfying -- something along the lines of "Well you know, people move around a lot.".  He even repeated it later.  Weird.

Should I tip off the police?  I don't know they are stolen bikes at all, but a simple visit from a cop could potentially end a long-time bike thief's spree.  ("Where did you buy these bikes / can I see a receipt / etc").

Or, maybe he has some legit story that he just didn't want to tell me (he gets them free (craigslist?), or has an ebay addiction, etc.) and I should mind my own business.

What do you think?

Provide a brief overview of the text.
<bot>: Some sketchy guy might be stealing bikes, or might not be.  Should I report him to the police or mind my business?