Howdy @Jon Horton
Wow. Talk about jumping in over your head. Where can I start.
Financing. How would you plan to finance this deal? A commercial lender would not take this for several reasons. You would have to put at least 25% down. You also be required to have a cash reserve. You do not have either. So would the seller provide owner financing? If they did you still need a cash reserve. The lender may also require you have experience managing properties. Your best option is to find an experienced partner.
Your CapEx budget will be astronomical. Why? Because you must be prepared to repair/replace 96 roofs, HVACs, Water Heaters, Refrigerators, etc. Along with covering mortgage payments when properties are vacant. That's why you need a cash reserve.
Property Value. We do not use the tax assessed value to determine the Fair Market Value of properties. Appraisals are used to determine the current value. Zillow is not a good source either. They do not keep their data up to date. That being said. If the seller is using the assessed value for the Asking price that's good for you. Appraised values are almost always higher. Strongly recommend you find a good "investor friendly" Realtor/Broker and a good Property Management company to help assess and manage this type deal.
Finely, there are many BP investors (myself included) who stay away from these type properties (small/$30K homes). Mainly because of the potential CapEx cost compared to the minimum income they produce. That's not to say we haven't purchased properties for $20K - $25K. The difference for me was after I Rehab them the value is closer to $100K.
The bottom line. If I were you I would not jump into this by myself. Try to find a partner experienced with this type of deal. Learn from them. Good luck.