I worked out a deal with him to purchase the home for $170,000 (City assessment was $230,000) and he would full finance the mortgage at 4.5% for a 4 year term (interest only, I could do principle if I wanted without penalty).

Suppose each one is assessed for $20k each and I put all 100 properties on the market for $20k each.

I thought that was worth it, but I wasn’t sure what the “norm” is, or what other criteria have for assessing.

Insurance that covers special assessments is something I've never heard of.

Then assess would that even been a good deal?

The city assessed it as a 3/1.5 (2 full bathrooms, 1 is in basement).But he said there was only 2 bedrooms.

Is your monthly tax payment based on today's tax assessment or tomorrow's tax assessment?

Sounds like your mom didn't buy the property that long ago, but California allows children to receive property with their parent's assessed value of the property, with certain exceptions.

Sounds like your mom didn't buy the property that long ago, but California allows children to receive property with their parent's assessed value of the property, with certain exceptions. 

Gives you a great assessment of the varying levels of risk in each neighborhood you look at in that market.