However, when the hikes take effect, my ability to raise the rents will be closer at hand corresponding with the end of these current leases.I am going to have an attorney discuss with me my options for dealing with the cleaning fee issue with the current owner and determine if there is something we can work out to make both parties happy with continuing with this deal. 

And he started as a leasing agent.. you simply cant do that as a wholesaler in a market where you need a license to bring two parties together for expectation of compensation..  

My financial situation has changed since then and I can no longer afford to pay a 3rd party company to send mail for me.

The only third party involved should be your home inspection.

Welcome to the party @Moses Brach! 

After that we will rent to unrelated parties. 

Perhaps a nice 1950's built bungalow.Always hire a 3rd party property inspector to give you an unbiased feel for the home.

If I wanted to buy the property for cash, what makes the most financial sense for all parties involved?

But I would also like to make some money off of it with minimal effort on my part. 

He said both are highly unlikely to happen since the city already pushed them off to the builder, and there is no value in the parcels for a 3rd party to want to own them.