” (35 ILCS 200/15-175) The amount of exemption is the increase in the current year’s equalized assessed value (EAV), above the 1977 EAV, up to a maximum of $7,000 in Cook County and $6,000 in all other counties.Our scenario is my mother and step dad live in a SFR of ours and their rent is solely based on the total costs of the property (mortgage, insurance, and property taxes).

I live in Danville IL and it looks like everything is for sale low prices homes rent ready anywhere from 15 to 30k and of course your older run down houses 3-10k all different types of houses in different conditions.

I just increase my rents by $50 and say water is included, job done.

The price has increased quite a bit around 50%.  

BRRR is the strategy to grow our portfolio, ideally we can increase the number of cash flow streams and cash on hand to rinse and repeat.  

Is there potential to use it for AirBnB or some other short term arrangement to increase the income?

There WILL be other deals.Your knowledge/experience WILL increase with time.There's no reason why your Flipping101education NEEDS to be expensive.ie.

Secondly, you will almost always get more bang (read: bigger rent increase) when you upgrade amenities (say new cabinets or flooring) between tenants.That said, in my books there are exceptions for long-term tenants.  

I shouldn't have said that it increases the cap by 1%, but just using that as an example to show how big of a difference it makes.This will double my # of units, so just want to make sure my numbers are tight.

Counties reassess property with significantly higher values annually, and local governments assume that they are entitled to a corresponding increase in spending.