At this point you definatly need an attorney but in the future I recommend that you don't exclude Section 8 but you do consider Section 8 as a portion of their income and they must still meet your income requirements.

In general, I cannot imagine you lease has language specifically excluding sale of property from renewal talk, AND even if it did you are not selling mid lease. 

No one is excluded from this.  

Make sure you exclude certain breeds.

It's perfectly legal and it's actually your job to discriminate against anyone else you don't want to rent to, which normally includes people who don't appear able to pay the rent or get along with their neighbors.But, there is no law against you saying you only want a cetain type of tenant, as long as it doesn't exclude someone on the protected class list.

The list of excluded items are so extensive that judgement are very rarely collected. 

They EXCLUDED all Section 8 payments (logic being those are always paid on time anyhow, so they were excluded). 100% of my landlord friends (and me) have 100% collections here in Northern Colorado.

If not excluded, then it’s generally covered.  

-Business pays income tax on whatever is left after that, which excludes the $80K.Does this makes sense? 

Therefore supply will be in a real odd space for a while excluding a few outlier areas or states.