Otherwise, if you're assuming third party management, then maintenance is either baked into their fee or charged hourly like a vendor. 

My background involves social work & non-profit management before getting into real estate.

They both involve sourcing deals.  

These have a much higher CoC ranging from 18-30% depending on how involved you are, the property specific and its execution from a design/amenity standpoint to management.  

My name is Jared Smith and I have been involved in various real estate investments since 2006 when we did our first flip in the PNW all on a CC!

However, splitting the cost as Jeff suggested may get things fixed up quickly and keep the peace between both parties.

You may want to involve an attorney for the purchase and sale and mortgage agreements though... 

It would be worth paying a third party to go and check the work for you to confirm it's completed before sending the funds. 

We found ourselves wasting an obscene amount of time doing our due diligence where we doubt that the vast majority of bidders actually understood the costs involved in the rehabs.

Most serious and qualified tenants are searching on the major 3rd party platforms you mentioned + realtor.com, redfin, and a few others.Apartments.com & homes.com are owned by the same company and may offer some additional marketing options.Another strategy to consider here is social media - video marketing.