How to Calculate ARV for flips in a buy & hold town?

[Scott Le]

I live in Tampa, which is a red hot market for buy and hold investors buying foreclosures for cheap and then renting them out. The problem is that because of this dynamic, finding comps to calculate ARV for flips has been extremely difficult. The only comps MLS finds are the "before" prices (as in a "before & after"), which don't tell me anything about ARV since they are only the foreclosure prices. There are definitely people flipping, but for the most part I have no idea where they are getting ARV from (and they are outnumbered by buy & hold anyway).

Another problem with Tampa compounding my problem is how hit or miss so many of the neighborhoods are.  There are some nice neighborhoods with well taken care of homes, but then you could drive down 2 blocks and be in a real bad neighborhood.  This means I really can't expand my search radius very far when looking for comps because the area can generally change drastically from block to block.  This just makes finding comps even more difficult since the search radius has to be so small.

I'm trying to flip my first house (inability to get a mortgage means buy & hold isn't really a viable option for me).  However, everytime I see a listing, I can't find any comps and I don't wanna get stuck guessing on what a house could sell for.  Does anyone have any experience flipping in similar rental heavy markets?