Let me know if you need me to run by the property and get you a video of the site.

However, there are some out there that will use AirDNA type sites to calculate income. 

  So these are not the homes on HUD site where they list their homes for sale? 

And there may be somewhat of a combination of site improvements included (sewer/septic, water service, etc, to the MH sites).Then the income approach would be looking at the cap rates, as Roger mentioned.

Get a website, and use that money to build up your site.

Many of the moderators of the site have experience with seller finance. 

Online Auction Sites - Realauction.com, LLC 

As for comps, if there are other modular homes in the area you may want to check sites like Zillow or Redfin to see if there is data on those properties. 

get a copy of the agreement used by agents in your area and merge it with wholesaling agreements you can discover on Jerry Norton's site.

True foreclosures are all cash purchases so if you don't even want to pay $25 for a list or for access to a good site, you are probably starting a long climb up the wrong tree.