$1000 houses in Buffalo

[Dominika M]

Hi all,
When i search homes on mls.com in Buffalo and sort from lowest price to highest, there are several pages of houses for $1000. What's up with that?
I understand that there's a large number of houses slated for demolition in Buffalo - I guess these may be such houses. But people on BP seem to do wonders buying very run down properties and doing gut flips. So i wonder why 5 of these at a time aren't snapped up for a big project.
Please give your thoughts on areas that are not investable. How bad is too bad.
Thanks all,