😁Some of my best deals have been crazy low ball offers and they’ve been accepted.

depends how the agreement is setup. sometimes people charge a premium to accept rent by weekly, in that case rent is due every two weeks. at $500 monthly you would collect an extra $250 per year. if rent is due on the 1st and 15th of the month, you only collect rent twice per month regardless of number of weeks.are you a renter or a landlord asking?

So I would think this is only an acceptable investment property if you either have a value add (you did not indicate a value add), are very confident of market appreciation (I am not at this point), or are vary confident of rent appreciation.I would not purchase it as a potential rental. 

This is my second deal, and here is a general outline of what has happened:Mid April: I put in offers to buy the rental property.Late April: Seller accepted offerEarly May: PM/ seller dragged their feet through availability for inspections/ appraisal. 

They have zero incentive to negotiate with you or even to just accept your payments. 

I explained that my partner would be funding the majority of the down payment, but she said that I can't just accept a transfer of money from her to help fund the down payment.

I just got my first offer accepted on my first duplex. 

What will they do to get your offer accepted?

Would a 50-50 split be acceptable?

You should get financing first, through a lender of some sort, then can you start seriously looking at properties, because most sellers will not accept offers that are not pre approved for financing.